Aero Glass Crash in RC1 with Perf Rating 4.0

Hi,

I am currently running Vista RC1, however, whenever I try to turn on Aero
Glass with Transparency and Desktop Composition, I get a total unrecoverable
system freeze.

Perforamance Analysis says my system rating is 4.0, with 5.9 for Aero, so I
don't understand why this always occurs.

I have updated to the nVIDIA Vista drivers, however the problem still
persists with either Microsoft or nVIDIA drivers installed.

My GPU is an nVIDIA 256MB 6800GT AGP
My CPU is an AMD Athlon 64 3200+
I have 1 GB RAM.

I tried to use Beta 2 and encountered the same problem and thought that this
would be rectified in RC1.

Any thoughts?

Thanks, Ben