ASUSTeK Computer Inc.-Forum- Crossfire issue with latest drivers

Hi,

I have 2 4850/1GB individually they work great on the latest drivers.
To use crossfire I have to uninstall CCC an use ATI Tray Tools (don't mind that bit) but I also have to run drivers from early 2008 (found 8.5 to be best). However the latest games are complaining about out of date drivers and in some cases glitchy or crash.

My two cards are suppose to be identical (both part no. 90-C1CL55-LZUAY00Z)

however gpu-z is showing differences between the cards (can't figure out how to post a screenshot here).

and the BIOS appear to be different

Card 1 has BIOS - 9442.11.6.0.3.AS05 dated 09/23/08 (seems to be latest from ASUS)
Card 2 has BIOS - 9442.11.13.0.2.AS01 dated 02/20/09 (can't find any existence of this BIOS anywhere online.

GPU-Z also states Card 1 is running at 625MHz but 2 at 725MHz by default (and Crossfire enabled when running under early 2008 drivers).

I have tried to load Card 2 BIOS on Card 1 and Card 1 just stops working (funky colours and alsorts starts happening)

Card 1 BIOS on Card 2 Windows boots with crossfire disabled and I have the option to enable but windows crashes with the message 'The display driver appears to be in a loop' or words to that effect.

Any help welcomed as I'm wanting to go to win7 and fear further problems and lack of 2008 drivers

My System

AMD Phenom 9500x4 @ 2.51 GHz
4GB of RAM
x86 Win XP SP3 (Tried earlier versions)
(aware 4GB pointless on 32bit but intend to upgrade to 64bit win7)