This has probably been asked and answered but my search met with negative results.  When I'm playing a game on my PC I get a short "beep" through my speakers and the key on my keyboard I was HOLDING down "sticks".  For clarification, the button does not actually stick, it will rise back to its normal position.  However, even though the key will return to its normal position, it's as though the key is still being pressed (i.e.  if I was holding the "w" key, my character in the game will continue to move forward).  This happens with other keys that are normally held down during game play as well.  If I tap and release the "STUCK" key the problem goes away, however, seconds or minutes later it will reoccur.  This only happens when I am playing a game and has occured in every game I play (BF2, Oblivion, HALO, Ghost Recon Advanced Warfighter, and Dark Messiah Might and Magic).  I just built my PC a few weeks ago and this has been a problem from the start.  I'm not experiencing any other problems at all.  I have tried SWAPPING out the keyboard and this did NOT correct the problem.  I have tried unstalling and reinstalling the software that came with my keyboard, with negative results, and made sure it is the most up-to-date version.  My PC specs are as follows:

EVGA nForce 680i SLI motherboard
Intel Core 2 Extreme Quad Core (QX6700) processor
2 GB Corsair Dominator 800 MHz PC2-6400 memory
Two 150 GB Western Digital Raptor HDDs in a RAID 0 array
One 320 GB Western Digital Caviar HDD for backup and data storage
One EVGA eGeForce 8800 GTX  graphics card
Logitech Elite PS2 keyboard

Windows XP Pro SP 2
Norton Internet Security 2006
Spyware X-terminator 2005

I would greatly appreciate any suggestions for correcting this problem.  How long do you hold the key down for before the problem happens?
Do you have any accessibility options on?
And . . . wow, nice PC Thanks for the reply and comment on my machine Calum.  You can imagine how frustrated I am after dropping all that $$ for it and then having to deal with this little problem.  The frequency that my "stuck key" issue occures and the duration that a key needs to be held down varies greatly.  Sometimes I can play for several minutes without this happening at all.  Then all the sudden I get the "beep" tone through my speakers that I mentioned and Im tapping the stuck key to get my character to stop moving.  I'v tried holding a key down while moving in the same direction or walking into a wall for up to 20 seconds in an effort to duplicate it and somtimes it will happen, sometimes not.  I'v also tried to duplicate it by holding down a combination of keys (such as Shift+W to run forward) and I get the same inconsistant results.  The checkboxes for StickyKeys, FilterKeys, and ToggleKeys are all unchecked under the Windows Accessibility Options.  Any suggestions or other questions?  Please let me know.So another keyboard on that PC does the same thing . . . how about that keyboard on another PC?
Try swapping it to another port?
Reinstall the drivers too.I will have to find another computer to swap my keyboard to since I can't use my old one.  I cannibalized the power supply from it for my new machine.  I'm just having my doubts that it's the keyboard since swapping it out with another one had no effect.  It's a PS2 keyboard and the only other PS2 port I have on my I/O panel is the one for a mouse.  Should I plug it into that one and see what happens?  I already tried removing the software that came with the keyboard and reinstalling it.  This didn't FIX the problem.  I figured the drivers would be included in that.  If the drivers are somewhere else where would they be?  Thanks again.