Well I posted DXdiag etc on the UBI tech forum.
Turns out I couldn't see the wood for the trees, I had tried everything, and missed the obvious.
When they replaced the motherboard, instead of putting my 2.8 P4 back in, they put in a 2.8 Celeron
Loads of apologies when I called, they are coming Monday afternoon, to gimme my P4 back, so problem will be solved
Perhaps they thought I wouldn't notice, and I didn't
Thanks Coastie
Moral: If you take your PC to a repair shop, make sure you at least get it back, as good as it was




