Issue With Controls

[Kon-Tiki]

I dunno if this is the right place, especially as it's not development-wise.I like to play Flash games now and then to fill up an empty half an hour. A problem I frequently have, though, is that when I move the character around (cursor keys or mouse, depending on the game), it often kinda goes tilt and keeps walking in one direction, or seems as if it's controlled by somebody else, walking all over the place without me giving any input (especially happens when pressing one direction for a few seconds, to make it walk in that direction for a bit). That half an hour of relaxing during an empty time quickly becomes half an hour of stress and frustration because of that. I got it with quite alot of games, spread over different sites (although some seem to have it worse than others). I use Firefox, and had it in both the latest version and some previous versions. Dunno if it does that in IE, as I haven't tried there.Anybody here knows what causes this and what I can do 'bout it? It makes so many games near-impossible to play.