Hi was going of your sig my mistake, check to see what your memory voltage is and timings and set them G.Skill 4GB DDR2 PK PC2-8500C5 (2x2GB) x2 memory voltage 2.0-2.1v, memory timings 5-5-5-15.and up your Northbridge(mch) voltage +0.1v since you are running four stick,s.