Letter keys stop working

After five seconds of play, the letter keys cease to work. If I re-start the game, the letter keys work again, then stop working after five seconds again. The letter keys work fine outside of the applications in the list below. This problem occurs in:

new caps

old caps

games exported from construct

games exported from Multimedia Fusion 2 (made by other people)

And this happened just after installing service pack 2 & 3 for windows XP.

(I tried uninstalling service pack 3, and the problem persisted, so I know it's service pack 2 that's the problem)

So I ask ye now, does anybody have any clues as to what might be the matter?

Sounds like a Direct Input problem.

I recommend installing the latest Direct X version to see if that solves the problem.

What kind of keyboard is it? If it uses special software to make it work, try uninstalling that software, it could be causing a conflict with Direct Input.

Hope that helps.

~Sol