ATI problems

On april 24 I installed the win7 rc1 x64bit OS on the following PC configuration -
Alienware M17-EU notebook (CPU - core2duo T9400,GPU - dual ati mobility radeon HD3870X2 crossfireX enabled,250 HDD,4GB ddr3 RAM) .
I have the following problem - as the computer has 2 video cards,it works fine under vista x86 and x64,running both of them,but not under win7 x64. The secondary video card fails to start at all,giving me (Code10) as explanation. Win7 didnt manage to install the drivers itself at the system setup so I uninstalled and downloaded the ones from ATI.
However,they dont seem to get it going either.
Any suggestions on how to fix this problem?

Do you still get a Code 10 can't start error with the latest ATI drivers, or was it a new error? I've tested Crossfire on an x64 Win 7 machine and it seemed to work ok in that instance.

ATI/AMD are developing drivers for Windows 7 and have been for some time, so the drivers should be relatively bug free.

Yes,I do,even with catalyst 9.4 . I did a clean instal on the drivers every time so something doesn't bug or such but it still didn't work. I'm on build 7022 now,just wanted to check if something was wrong with my graphics cards. Well,they're fine. Under build 7022 they're both recognised and operational,no problems whatsoever. My best guess is that there might be a problem for the mobility hd3870x2 in build 7100.Can't say more really...