i have recieved a beta bios from msi (1.D4) and my graphics card has now been returned. msi claimed that the beta would fix the problem, however, after updating ym bios, re installing my 5770 and loading up a fresh coppy of windows 7 i am still having the same problem and i am getting really pissed off now because everything was running perfectly when i had the 7600gt in there and now i have the 5770 back we are back to square 1 again and ebuyer dont seem to care anymore :s
Hey man, I have the same problem you do but I think I found the answer. I actually have a very similar setup to you too:
AMD Phenom X4 3.2 GHZ
Saphire Radeon 5770
MSI mobo 790 (same as yours)
After trying lots of stuff it boils down to one of two things:
Your CPU NB Speed MUST BE HIGHER than your Hyper Transport Link Speed.
I clocked my CPU NB to 2200 MHZ and left my HTLink at 2000 MHZ.
Once that is done, MSI mobos also seem to have a problem properly regulating voltage to the CPU and CPU NB. I recommend:
1.) Change your CPU-NB clock speed multiplier up one step and ensure that it is higher than your HTLink clock speed
2. ) Raise the voltage by ONE step to your CPU-NB.
3.) if the error still occurs raise the voltage by one step to everything (ram/cpu/cpu-NB).
Like I said I had the same problem as you, and ever since I changed my CPU NB to exceed my HTLink as well as upped the voltage one notch to my CPU NB the problem seems to have gone away, so try that first before you raise the voltage anywhere else.
Will report back if I find anything else. However, I strongly believe that ultimately this boils down to a voltage issue, and MSI/AMD not properly regulating voltage to the CPU/CPU NB/or potentially to the RAM.
Benny