Oh, here something that hasn't bothered me much, but something I noticed on day one of using my NKRO 87-cherry Filco Majestouch.
I insist on using it through PS/2 because on my system, the input lag is noticeably less than USB; the repeat rate is higher as well.
Occasionally, I get any of the shift/alt/ctrl/win keys stuck in its down state, in WinXP Pro 32bit. I have many global hotkeys with those keys as modifiers, so I tend to notice.
Mashing each independently corrects it, because I don't care to deduce which is stuck whenever it happens; just unstick them all.
At any rate, it's hard to reproduce at will, but seems to happen regardless of the application. The fastest way to induce it however, is to load up
http://random.xem.us/rollover.html and register some silly keycount like 40+. Then switch to say, notepad, and notice that typing anything either does nothing because Ctrl is down, or you get uppercased letters because Shift is in its down state, etc.
Anyone ever get this sort of weird state? It might be related to
this thread...