Binary package hint: xorg
This was originally filed as a Wine bug, but I have recently determined it to be a more general bug in X, if someone can prove it otherwise, please do, do help narrow things down.
Anyway, occasionally when in an OpenGL application, Games, for instance... a Button with magically begin to repeat itself, as if being held down. It could be the up arrow, 1, 2, w, q, z, whatever, it's a general issue. It rarely happens right off, but seems entirely random when it occurs. It has been seen in both native and non-native (non-native-ish (wine)) OpenGL applications, and is becoming a real plague to gaming.
I can't offer very much specific information, I mean this is a hard thing to trace. Myself I mainly see it in Wine, but that is where I spend most of my time as far as gaming goes, and it has been witnessed by others in native applications, and found true by myself in trials.
After closing the application in question, the key remains repeating, sticking, if you will. For example, if it were the 'up' key, and I made it back to my terminal, the behavior would be scrolling through my type history. you get the idea on how that works most likely.