Sounds like the ballpark to look in, neither of the pcs are acting up at all, I think they have a thing in Bios spelt differently, like "APCI" or something.
I was wondering if it was coz I selected "Standard pc" on one of them - but then on the otherone it`s installed as "ACPI Multiprocessor" - so meh..
It`s something to do with this, must be.