Why is iTunes starting and stopping play randomly, and how do I stop it?

Question

Since yesterday morning my copy of iTunes has been starting and stopping randomly. If iTunes is not running, then it opens and sometimes begins playing, other times sits idle. Eventually, after a random interval it will begin playing a song, and then stop, and so on... Needless to say, it's driving me mad.

(Mac OSX, 10.6.3, on a new-ish (< 1 year old) 24" iMac)

I've made five changes to my system that may or may not be connected to this:

1. My office phone was replaced with a Linksys IP Phone, which necessitated a change to my networking; where previously my Mac was connected directly to the office network port, now it is connected through the phone.

2. My network connection now uses auto link detection in lieu of forcing 100Mbit

3. I unpaired my bluetooth headset.

4. I removed the USB audio device associated with another headset.

5. I upgraded to Safari 5. I don't use it as a primary browser, but it's often open to run web apps that I'm developing.

All of these things happened in pretty close proximity to each other, so one or more of them may be the culprit.

One other thing that may or may not be related; for some reason my built-in microphone is no longer picking up audio. It seems like this might be connected to the iTunes issue, because it happened around the same time.

In terms of things that I've tried in order to solve this, I'm at a bit of a loss. I followed the instructions at http://developer.apple.com/mac/library/technotes/tn2004/tn2124.html#SECLAUNCHDLOGGING to enable detailed launchd logging to see if I could track down which process was asking iTunes to open (when it's not already open) but I wasn't able to make heads or tails of the output. I'm not even sure if I'm looking in the right place, to be honest; it actually acts like something is activating the application with AppleScript, but I have no processes running that are doing that, as far as I know.

I'm running a few apps that have iTunes integration: Adium, iChat with Chax, Quicksilver. None of these have been changed lately, so I consider them low risks of causing this, but it's not impossible. Moreover, I'm not using any of those features intentionally.

This is a snippet of launchd debug logging from around the time it just launched:

10-06-09 9:14:29 AM com.apple.launchd[1]    Dispatching kevent...
10-06-09 9:14:29 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x10002b230 data = 0x30 ident = 5 filter = EVFILT_READ flags = EV_ADD|EV_RECEIPT fflags = 0x0
10-06-09 9:14:29 AM com.apple.launchd[1]    Dispatching kevent...
10-06-09 9:14:29 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x100802000 data = 0x0 ident = 26 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK
10-06-09 9:14:29 AM com.apple.launchd[1]    (com.apple.coreservicesd[26]) Dispatching kevent callback.
10-06-09 9:14:29 AM com.apple.launchd[1]    (com.apple.coreservicesd[26]) EVFILT_PROC event for job:
10-06-09 9:14:29 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x1004076f0 data = 0x0 ident = 26 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK
10-06-09 9:14:29 AM com.apple.launchd[1]    (com.apple.coreservicesd[26]) fork()ed
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave) Conceived
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Created PID 22197 anonymously by PPID 26
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Looking up per user launchd for UID: 0
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Per user launchd job found for UID: 505
10-06-09 9:14:29 AM com.apple.launchd[1]    System: Looking up service com.apple.system.notification_center
10-06-09 9:14:29 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.notification_center
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Looking up per user launchd for UID: 0
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Per user launchd job found for UID: 505
10-06-09 9:14:29 AM com.apple.launchd[1]    System: Looking up service com.apple.system.DirectoryService.libinfo_v1
10-06-09 9:14:29 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.DirectoryService.libinfo_v1
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Looking up per user launchd for UID: 0
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Per user launchd job found for UID: 505
10-06-09 9:14:29 AM com.apple.launchd[1]    System: Looking up service com.apple.system.DirectoryService.membership_v1
10-06-09 9:14:29 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.DirectoryService.membership_v1
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Looking up per user launchd for UID: 0
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Per user launchd job found for UID: 505
10-06-09 9:14:29 AM com.apple.launchd[1]    System: Looking up service com.apple.CoreServices.coreservicesd
10-06-09 9:14:29 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.CoreServices.coreservicesd
10-06-09 9:14:29 AM com.apple.launchd[1]    Dispatching kevent...
10-06-09 9:14:29 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x100802000 data = 0x0 ident = 22197 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_EXIT
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Dispatching kevent callback.
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) EVFILT_PROC event for job:
10-06-09 9:14:29 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x100401720 data = 0x0 ident = 22197 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_EXIT
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22197]) Reaping
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave) Total rusage: utime 0.000000 stime 0.000000 maxrss 0 ixrss 0 idrss 0 isrss 0 minflt 0 majflt 0 nswap 0 inblock 0 oublock 0 msgsnd 0 msgrcv 0 nsignals 0 nvcsw 0 nivcsw 0
10-06-09 9:14:29 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave) Removed
10-06-09 9:14:30 AM com.apple.launchd[1]    Dispatching kevent...
10-06-09 9:14:30 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x100802000 data = 0x0 ident = 22197 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR|EV_EOF|EV_ONESHOT fflags = NOTE_REAP
10-06-09 9:14:32 AM com.apple.launchd[1]    Dispatching kevent...
10-06-09 9:14:32 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x10002b230 data = 0x30 ident = 5 filter = EVFILT_READ flags = EV_ADD|EV_RECEIPT fflags = 0x0
10-06-09 9:14:33 AM com.apple.launchd[1]    Dispatching kevent...
10-06-09 9:14:33 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x100802000 data = 0x0 ident = 143 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK
10-06-09 9:14:33 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Dispatching kevent callback.
10-06-09 9:14:33 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) EVFILT_PROC event for job:
10-06-09 9:14:33 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x10041e9a0 data = 0x0 ident = 143 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK
10-06-09 9:14:33 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) fork()ed
10-06-09 9:14:33 AM com.apple.launchd[1]    System: Looking up service com.apple.distributed_notifications.2
10-06-09 9:14:33 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.distributed_notifications.2
10-06-09 9:14:33 AM com.apple.launchd[1]    System: Looking up service com.apple.system.notification_center
10-06-09 9:14:33 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.notification_center
10-06-09 9:14:33 AM com.apple.launchd[1]    System: Looking up service com.apple.system.DirectoryService.libinfo_v1
10-06-09 9:14:33 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.DirectoryService.libinfo_v1
10-06-09 9:14:33 AM com.apple.launchd[1]    System: Looking up service com.apple.system.DirectoryService.membership_v1
10-06-09 9:14:33 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.DirectoryService.membership_v1
10-06-09 9:14:33 AM com.apple.launchd[1]    System: Looking up service com.apple.CoreServices.coreservicesd
10-06-09 9:14:33 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.CoreServices.coreservicesd
10-06-09 9:14:33 AM com.apple.launchd[1]    System: Looking up service com.apple.SystemConfiguration.configd
10-06-09 9:14:33 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.SystemConfiguration.configd
10-06-09 9:14:33 AM com.apple.launchd[1]    System: Looking up service com.apple.audio.coreaudiod
10-06-09 9:14:33 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.audio.coreaudiod
10-06-09 9:14:34 AM com.apple.launchd[1]    System: Looking up service com.apple.system.logger
10-06-09 9:14:34 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.logger
10-06-09 9:14:35 AM com.apple.launchd[1]    Dispatching kevent...
10-06-09 9:14:35 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x10002b230 data = 0x30 ident = 5 filter = EVFILT_READ flags = EV_ADD|EV_RECEIPT fflags = 0x0
10-06-09 9:14:35 AM com.apple.launchd[1]    System: Looking up service com.apple.DiskArbitration.diskarbitrationd
10-06-09 9:14:35 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.DiskArbitration.diskarbitrationd
10-06-09 9:14:35 AM com.apple.launchd[1]    System: Looking up service com.apple.system.logger
10-06-09 9:14:35 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.logger
10-06-09 9:14:36 AM com.apple.launchd[1]    System: Looking up service com.apple.FSEvents
10-06-09 9:14:36 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.FSEvents
10-06-09 9:14:36 AM com.apple.launchd[1]    System: Looking up service com.apple.SystemConfiguration.configd
10-06-09 9:14:36 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.SystemConfiguration.configd
10-06-09 9:14:38 AM com.apple.launchd[1]    Dispatching kevent...
10-06-09 9:14:38 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x10002b230 data = 0x30 ident = 5 filter = EVFILT_READ flags = EV_ADD|EV_RECEIPT fflags = 0x0
10-06-09 9:14:39 AM com.apple.launchd[1]    Dispatching kevent...
10-06-09 9:14:39 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x100802000 data = 0x0 ident = 26 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK
10-06-09 9:14:39 AM com.apple.launchd[1]    (com.apple.coreservicesd[26]) Dispatching kevent callback.
10-06-09 9:14:39 AM com.apple.launchd[1]    (com.apple.coreservicesd[26]) EVFILT_PROC event for job:
10-06-09 9:14:39 AM com.apple.launchd[1]    KEVENT[0]: udata = 0x1004076f0 data = 0x0 ident = 26 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK
10-06-09 9:14:39 AM com.apple.launchd[1]    (com.apple.coreservicesd[26]) fork()ed
10-06-09 9:14:39 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave) Conceived
10-06-09 9:14:39 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22211]) Created PID 22211 anonymously by PPID 26
10-06-09 9:14:39 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22211]) Looking up per user launchd for UID: 0
10-06-09 9:14:39 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22211]) Per user launchd job found for UID: 505
10-06-09 9:14:39 AM com.apple.launchd[1]    System: Looking up service com.apple.system.notification_center
10-06-09 9:14:39 AM com.apple.launchd[1]    (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.notification_center
10-06-09 9:14:39 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22211]) Looking up per user launchd for UID: 0
10-06-09 9:14:39 AM com.apple.launchd[1]    (0x100401720.anonymous.lssave[22211]) Per user launchd job found for UID: 505
10-06-09 9:14:39 AM com.apple.launchd[1]    System: Looking up service com.apple.system.DirectoryService.libinfo_v1

Answer 1

I think I may have found the problem:

When I switched out the network connection, I seem to have loosened the headphone or mic cable to my external speaker. This results in OSX detecting the disconnection and reconnection of the audio devices, and (for some reason) causing iTunes to start and stop playback -- irrespective of whether iTunes was running in the first place.

So, in summary, in case this happens, check your mic and speaker connections.