@ wick 001:
That is a common problem man, and will be mentioned in the release notes for 9.2 Basically anything from 8.12 onwards doesn't work for quad crossfire (your two beastly 4870x2s) so you need to revert to the old 8.11 drivers in the meantime. Gash, I know and all you can do is wait for 9.3 and hopefully a fix.
Go to the AMD website to see the release notes and go to the forum to read up on what I said, all the newest threads are by ppl like you ranting about why only 3 cores work!
http://forums.amd.com/game/categories.cfm?catid=279
@everyone else:
I reckon I'll stay with my 8.10 drivers - these 9.2s look like they f*ck more things up than not - and if you look on their forum there are ppl kicking up a sh*tstorm. Poor, poor driver support - that really is an area where you see Nvidia take the lead