I have a new PC with XP pro 64bit installed and its driving me mad!

The machine seems to work just fine but with one rather annoying exception.
The only applications that will take keystrokes are 'Internet Explorer
(64-bit)' and 'notepad'.

Typing on the keyboard in any other application simply hangs that application.

BTW: Everything looks fine in device manager.

I dont know what I can do to resolve this, at the moment its pretty much
just an expensive ornament.

SPEC:
Motherboard:     ASUA Maximus Formula
Processor:         1 x Intel Core2 Quad CPU Q6700 (2.66Ghz)
Memory:            4 x 2GB
HDD:                 4 x 750GB RAID 10 (resulting in around 1.4TB)
Graphics:           2 x ATI Radeon HD 2600 PRO (driving 4x 19" TFT)
...and a few other bits!