Why does my keyboard's "F-lock" button turn itself off?

Question

My keyboard has dual-function F-keys -- each F-key has a word printed across the top (e.g. F5 says "Open"). I presume that on a MS OS these are mapped to these common operations. To use these keys as normal F-keys, there's an "F-lock" button and an LED that comes on to indicate F-lock is active.

I use the F-keys a lot -- they're mapped to various operations I perform in eamcs.

The primary annoyance is that the F-lock turns off frequently (maybe once an hour?), so I hit F11 (which is goto-line) and nothing happens. If I'm not looking at the LED, I usually end up following F11 with some number, and then I end up with that line number inserted into my file. (Or something similar with some other F-key.)

Sometimes the F-lock turns off while I'm typing. If this happens, I notice that the whole keyboard freezes (my keystrokes are lost), all the LEDs (F-lock, caps-lock, num-lock) come on, caps-lock (which is always off) and F-lock go off and num-lock stays on (this is intentionally always on).

What causes this, and how can I fix it?

• "Microsoft Natural Multimedia Keyboard 1.0A" (from ~2004), though I've seen this behavior with at least one other similar type of keyboard.
• Ubuntu 10.04 LTS with linux kernel 2.6.32, though I've seen this behavior on Centos with kernel 2.6.18 as well.
• It's a PS2 keyboard plugged into a PS2/USB adapter (along with a PS2 mouse).
• In my keyboard preferences, the keyboard model is set to "Generic 105-key (Intl) PC". I've looked at the available options for MS keyboards but this specific model is not mentioned (though "Microsoft Natural" is).
• There are no external USB hubs. At the moment, lsusb reports the following. Seagate is an external HDD. I think Upek is the fingerprint scanner. The problem described above still occurs if I disconnect the HDD, and I never use the fingerprint scanner. I can sustain about 60wpm copy-typing, much less when coding, but it seems like that shouldn't overwhelm the USB?

% lsusb 
Bus 002 Device 007: ID 0bc2:3008 Seagate RSS LLC 
Bus 002 Device 004: ID 0a81:0205 Chesen Electronics Corp. PS/2 Keyboard+Mouse Adapter
Bus 002 Device 003: ID 147e:1000 Upek 
Bus 002 Device 002: ID 8087:0020  
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 8087:0020  
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Update:

Per suggestions in comments below, I have:

• Replaced the PS/2-to-USB adapter with another unit. (Same brand, but different physical unit.)
• Removed the PS/2 mouse from the adapter and plugged in a native USB mouse to another USB port.

Even with these changes, it just happened again. There hasn't been significant activity on the external HDD, but I've also just disconnected that to verify that it is not the source of the problems.

Answer 1

I'm seeing similar strange behavior with the same PS2-to-USB adapter you're using, the "Bus 002 Device 004: ID 0a81:0205 Chesen Electronics Corp. PS/2 Keyboard+Mouse Adapter". My problem is that while I type, suddenly the keyboard goes into some weird "permanently-Shift-pressed" mode, which I have to press some funky key combination (which I'm not sure of, but it usually involves AltGr plus some other buttons) for it to reset itself back to normal. I've also noticed that it sometimes outputs a lot of repeated keystrokes, like you're holding down a key for several seconds (but you're not).

I'm running a Logitech iTouch PS2 keyboard on this USB adapter, and I'm using Windows 7 Pro x64, which in turn rules out your OS as well.

I would say we're both the victims of poorly manufactured hardware. I'm getting another adapter, for sure, but this time probably something manufactured by Logitech. I'm assuming they test their adapters with their own keyboards.

Just for the record. This keyboard never gave me problems when I used it on PS2.