i have suspicion could it be the following?-
card ram faulty
my motherboard revision,its an 1D1 with the timing fix
faulty card
Heating issues?
It could be a PSU issue (if your not using a Goliath), however sounds to me that it doen't like your RAM.
My 1230 did this when it didn't like the installed RAM (was working but obviously just a bit fussy).
Unlikely to be heating issues, especially if problems are occouring
that early.