Hypertransport sync flood error - how to diagnose?

Hi,

I'm thinking it may be the end of the road for my Biostar A880G+ motherboard which is a shame as it has done me well until this point. The problems started appearing after I shifted to a new case so that I had room to upgrade the GPU.

I think the two problems are related. The first is a fairly random lack of video output, also accompanied by unresponsiveness (you can't select options with the screen off) and the reset button stops working, which suggests motherboard to me. This was only occurring after the computer had been on for 6 or 8 hours - I tried re-seating the RAM modules and GPU and thought this had solved it but it has just happened again. It happens with my old GPU just as it does with the new one so GPU can be ruled out. All drivers bang up to date.

Second problem is hyptertransport sync flood error. Again this used to be pretty random but i have managed to trigger it consistently by playing Shogun total war (when it gets to the campaign screen). Company of Heroes 2 and Dawn of War retribution both play fine. I can handle being with total war but also need this computer for work so don't want it bumming out on me half way through doing stuff . What should I do!!????

Anyone? doesn't seem to be much info out there on these kinds of errors.

Strangely, the problems seem to have gone away again since i last posted. But I'm still concerned the system is unstable and might crash on me. Any advice?