I have just bought a P8P67 board based system and was on the point of returning the PSU and VGA crad when I found the following thread:
http://www.overclock.net/intel-motherboards/910402-asus-p67-series-information-thread-drivers.htmlAll the resources you will ever need (and updated) on page 1 and then 144 pages of discussion of the various problems and their resolution.
Believe me, if you buy a board with this chipset, you will almost certainly need this info. The one I bought that arrived last Friday had BIOS v1003 on it - the current is v1305 - so you can see how old it is, with around half a dozen updates in between.
BIOS flashing in the new EFI BIOS is very very simple. It's a matter of clicking on the EZ Flash update button, then simply browsing to the BIOS ROM image on your PC and clicking on it (just like in Explorer - only its from the BIOS itself).
Don't be disheartened by the number of pages in that thread - my issues were resolved by the time I got to page 14.
And now I am very happy with my awesome system!

Asus P8P67 Pro
Intel i5 2500K SandyBridge
Corsair XMS3 DDR3 1600 6GB
Gigabyte GTX560Ti OC
Corsair ModXStream 700W psu
HAF922 case
Big GRIN!

Flash