The guy called back when the problem was occurring - nothing showed up in the task manager.

I got a little more clarification from the user (it's always tough interpreting and translating the average user's computer terminology). Apparently when he starts having difficulty, he keeps seeing the menus in the menubars of his windows popping open. I haven't been able to determine if this is the only issue, or if this is just part of it. I told him it could be a stuck Alt key, and if the problem happens to give it a good heavy tap, but he called back later exasperated that that wasn't working either.

I may suggest that he try to find some way to disable the keyboard and trackpad altogether, and plug in a keyboard and mouse for the time being...

*edit*
Darn, need some help here. I was writing up steps on how to disable the keyboard, and following along on my system, but it doesn't appear that it's possible to disable a keyboard, is it? Uninstalling wouldn't do much good either because it would just reinstall immediately, wouldn't it? Any ideas?