Ctrl/shift 'sticky' problems XP - tearing hair out

I recently encouraged my parents to purchase a new evesham micro machine (PVR) which is excellent if you discount the numerous BSODs etc. Unfortunately since day one, there seems to be an issue with the ctrl, alt and shift keys. If you hold one down (unintentionally sometimes) it turns on an odd kind of mode which can only be solved by jabbing both sides (Left/Right Ctrl/shift/alt) until you can begin to type again.

I can hear a number of people scream 'ah, you've enabled stickykeys' under XP.

No, I haven't! All the boxes are unticked under the accessability options. The keyboard itself is a MS wireless multimedia keyboard. It is the bane of my life.

Help!

Have you got a bog standard keyboard to swap in and see if it's a keyboard error?

bought one today - I'll let you know. It's odd because it's consistant and undo's itself if you press the key a second time. It sounds like sticky keys, but isn't :- /

I've only ever seen that kind of behaviour with dodgy KVM switches (and sometimes with remote desktop clients).

PS/2 or USB keyboard? Tried both types?