movement s

I hoe that i can explain this corectly, but in a game like CoH, BF2, or Guild Wars i used to be able to hold down the "W" key to move forward the hit the "D" key to move right, but now when i hit the "D" key it stops moving forward. I then have to hit "W" again to move forward. Even if im moving forward and hit "spacebar" to jup i stop moving forward. Im suing a Dell Enhanced Multimedia Keyboard. Is anyone else having this problem? Is it the drivers for my Keyboard? (uptodate) is it just my keyboard? Or is there a setting that i havent found yet?