Crossfire problems

[James^.^]

Ive found a few problems on google pertaining to crossfire, but none fit my problem. First of all my specs are
biostar p45 i45
2x hd4870 (my problem)
e8400 (oc 4ghz)
800w psu

I got to click the enable crossfire box in ccc then the screen flickers black and comes back up like it worked (its not grayed out), but then i look at gpu-z and it says Disabled (crossfire available) and the 2nd card shows no load in gpuz or no activity in ccc (yes i know same thing)

I've already checked the pins double over
Ribbons are correct

if you guys have any solutions id love to hear

 

[mac550]

ok i dont know that much about ATI cards so soz if i cant something wrong.
first off, uninstall the drivers, let it restart and then shut it down, then try swapping the cards around, make sure there is no dust on the bridge or on the terminals of the cards, put the bridge(s) back and boot your system and reinstall the drivers and enable crossfire.
if that dont work then i have no idea.

 

[James^.^]

I actually already switched cards and reinstalled drivers. Im sure it's something to do with the biostar p45 motherboard, I think my best bet is to call them