okily dokily, ran memtest as suggested, and unsurprisingly it threw up errors. went in to bios and changed memory settings to auto, i had to originally select X.M.P (xtreme memory proflie i think) to get the ram to run at its full speed (1600mhz) on auto ito nly runs 1066. anyhoooo now that its back to aut,o prime95 and memtest run fine with no failures/errors. is there anyway to get the ram to run at its full speed without casuing the original problems?