I am running Leopard that I upgraded from Tiger.
I've been noticing that every once in a while the SyncServer process starts up and eats up all the CPU. The fans will start going at full blast and the laptop will slow down to a crawl. I need to force quit the process from Activity Monitor to get it under control. It disappears for a while, but eventually gets started again.
I do have an iphone as well that I sync so I'm wondering if syncServer might be an apple process checking for my phone plugged in.
Edit: Tried iSync and the manual resetsync as suggested, but got this output:
$ /System/Library/Frameworks/SyncServices.framework/Versions/A/Resources/resetsync.pl full
2010-03-12 08:03:50.230 perl[176:10b] SyncServer is unavailable: exception when connecting: connection timeout: did not receive reply
PerlObjCBridge: NSException raised while sending reallyResetSyncData to NSObject object
reason: "Can't connect to the sync server: NSPortTimeoutException: connection timeout: did not receive reply ((null))" userInfo: "" location: "/System/Library/Frameworks/SyncServices.framework/Versions/A/Resources/resetsync.pl line 16" ** PerlObjCBridge: dying due to NSException
And during that syncServer started spinning up 95-100% just like it always does.