Big Problems.

AMD 3200+xp
ASUS A7N8X-E-Deluxe
1GIG RAM
XFX 6800 ultra
PSU 550W

Ever since I've had my card I've had problems with instability on my
machine. Random Shutdowns being the main problem.
Shut down being, everything cuts out, but does not reboot. All fans
and drives shut down but CPU light remains on?

At first I thought it might be the way I arranged the power cables in
my machine (I have a 550w psu). After a bit of tinkering this seamed
to solve the problem for a while. Although blue screen crashes
appeared every so often, but not enough to bother me too much (twice a
month).
Lately the crashes got worse. I did not link these to my graphics card
as for a fairly long time it was stable. I've formatted my drives.
Re-installed everything afresh.
I have the latest drivers installed, and now it lasts about 3 minuets
in 3D mode and reboots. Or about 30mins in windows with no 3d.

Recently swapped MO'BO and Ram for New Versions of the same with my
local supplier, and still the same problem. My CPU runs fine in a
friends machine. But as soon as I put the card into his, he gets
instability (freezes) and random reboots.
And after a bit of tinkering in his bios, We dropped the CPU freq from
200 to 166. It was fine!!

Tried the same settings in my machine. Same MOBO (ASUS AN78N-DELUXE)
and slightly faster processor (AMD 3200+XP!
And had no luck and still the same problems.
Also tried new RAM But no change.

Running out of Ideas. I don't think the card is faulty as we had it
working in a friends machine. (and benchmarking higher than mine even
though its lower spec??!! )

But even with practically all new components in my machine we still
get the same problem (only old parts are HDD's, dvdrs, and soundcard)

Any suggestions, bios settings ?

Thanks
Max