BleepingComputer.com: unknown Key Commands (left SHIFT + W + D)

I was playing a game that required me to press and hold Shift + W + D and not only did it not respond but i got a beep (from speakers not internal)
It turns out that this (along with a few other combos) will cause this beep no matter what i am doing. even if i'm just on the desktop.
I've watched my running programs ( in task manager) for responses to these commands and the only program that seems to react to it is those that deal with outputing the audio.
the combo of keys is left CTRL or left SHIFT + any key in the second row from TAB to Y in combo with the key down and to my right of it E.G left SHIFT + W+D
The predictable pattern makes me thing it is a bug(or unfinished listener) in something, my first though is keyboard drivers.
I'm running Windows 7 x64 on an AMD processor. Keyboard is an old Ps/2 Emachines. Video card is ATI HD 4850.
Anyone know what could be causing this?

Thanks.

Have a dog or a two year old grandkid hold down keys if you want to hear noise
It's common

This post has been edited by garmanma: 11 January 2010 - 10:44 AM

garmanma, on Jan 10 2010, 10:17 PM, said:

It's just weird that it only happens with those combos. and that the third key isn't accepted as a press. (IE if I press shift + W + D i get a capital W and no D.)