Vista - Computer crashes with 3gb and 4gb DDR3 Ram, but works with 2gb and

Here are my pc stats. Proc. C2Quad 9300, Mobo DX38BT, 4gb RAM dual
channel (Kingston set of two 2gb strips, DDR3 1333), NVIDIA GeForce
XFX 8800GT 512mb ddr3, HD SG 750gb, PSU Satellite 600w, Windows Vista
Ultimate 32 (same problem happened under Win XP, and I´d be willing to move
up to Vista Ultimate 64).

Here´s the thing. When I turn on my pc with just ONE of the two memory
strips (2gb), or even when I try a different memory set (kingston 1gb,
set of two 512 DDR3 1333), the computer boots just fine. But when I do it with
both 2gb strips (4gb total), computer crashes on startup. Sometimes
the screen freezes when Vista is loading the startup apps, some other
times it doesn´t even get to that point and the computer just stops
working somewhere along the process and I get a blank screen.

Something else happened when I tried it with ONE 2gb strip and TWO 512mb
strips (3gb total). This time I got a blue screen. The message on the blue
screen said something like "There was an attempt to write on the read only
memory".

With WinXp (I switched to Vista to see if I could fix this problem)
the computer could boot (at a noticeably slower speed), but it would
just reboot when I played media files or opened a few browser windows
(I unchecked the "restart automatically" box to see if there were any
blue screens of error messages, but it would just reboot without any
of those, as if there was a power interruption). I already cleaned the fans
and heatsinks and tried the memory modules separately and there are no error
logs that suggest overheating.

I ran some memory testing apps and there doesn´t seem to be a problem
with the hardware, so I guess it must be something that needs to be
configured. Note that the Bios automatic memory setting seem to be wrong.
For instance, the voltage is set to 1.54, while the memory specs state that it
should run on 1.5. I tried to run it with different timings (changed it to
7-7-7-20 instead of the 9-9-9-24) but I still can´t get it
to work, in fact it crashed earlier in the boot process. Should I increase
the voltage? And if so, how much?

I read in some forum that this kind of memory, with this kind of fast
processor and this mobo can have some synchronization issues or things
that need to be fine tuned, but I can´t seem to find an expert on the
subject.

Sorry for the long post, but it´s desperate times! Ive been struggling with
this for almost two months now. Is anyone kind enough to give me a hand?
Thanks

"santiago83" <santiago83@xxxxxx> wrote in message
news:676C45F1-911C-4DC7-8E60-4923904119A4@xxxxxxYou have a hardware problem, not a software problem. Try running an OS -
independent memory test tool (Memtest comes to mind) and see what it tells
you. You seem to have tried several combinations of memory modules with
similar unsatisfactory results, so it may be a motherboard or BIOS issue.
Have you checked for BIOS updates that might be available for the DX38BT?
Have you checked to see if Intel has user forums for their products, like
here?

http://www.intel.com/communities/ind...dr+communities