I think I may have finally woken up to a (potential) cause for my random NumLock issues: the xine media player. One indicator, one that I really should have paid attention to earlier, is that often starting xine will turn on NumLock (and sometimes turn it off immediately afterwards). It is of course hard to be entirely sure since the problem is erratic, but I've been doing some testing since I noticed the correlation and I don't think I've ever had the problem when xine wasn't running.

I suspect that xine is not the only thing at fault, partly because this happens far more on my home machine than my work machine. It's certainly possible that xine happens to be the only program I usually run that does some particular operation that makes the X server hiccup in a way that toggles NumLock.

This is kind of irritating, since xine is what I use to play AAC+ music streams, and an AAC+ stream is what I tend to put on as background music at the office. With my keyboard, flipping NumLock on causes very wild things to happen in vi, and now that I have a strong suspicion, I should probably stop using xine at work.

(I can't say I'm exactly listening to the stream a lot of the time; one of the reasons I listen to this stream instead of actual music albums or the like is that I can stand to interrupt it at the drop of a hat. With albums, I get grumpy if I can't listen to them all the way through without interruptions.)

Mind you, the real cure may be to upgrade my ancient Fedora Core 6 installations to Fedora Core 7 (or wait a bit for FC8). That might even fix xmms's problems with AAC+ streams, which would make me happy since I am not entirely fond of xine.

(In the mean time, it appears that using mplayer gets me most of what I want. It handles AAC+ streams, it's verbose but non-GUI, and it uses both less memory and less CPU than xine. I'll call myself sold.)