Vista x64 hangs because of HD

I have a very special problem

Specs first
Intel E670
ASUS Striker Extrem
OCZ PC2-6400 2x1024MB 800MH
Fist HD (OS): Western Digital Raptor 74GB SATA 8MB 10000RP
*_Second_(storage):_Hitachi_Deskstar_500_GB_
The latter I cant find the exact name on because It bought it a lon
time ago..

Anyway, what my problem is that Vista hangs horribly if the 500gb hd i
in use. Virus scan, install software there, start it from that HD - jus
about anything that involves using that HD makes Vista hang
Both HDs are S-ATA, the latter is sata-300 (II). Both worked with th
exact same BIOS configuration with XP, and although I got a fe
bluescreens on XP that had to do with RAM timings, this HD never cause
any trouble. At the moment of writing the second HD is empty and unused
although plugged in. Since the cumputer is now running for over an hour
this my record of stabile operation to date with Vista x64, because i
would crash in the first 15 minutes of use otherwise
As a side note, I have the newest BIOS rom available installed, an
basicly did not do ANYTHING other than installing Vista. The SATA drive
is also installed, as provided by ASUS

What I did try is a complete format of that HD, but it did not help.
tell-tell sign of it hanging is constant HD activity on the cabinet`
led light

Any ideas on how I can get it working? :confused

--
im14