I did go back into the bios and set the memory from SPD to default, which deactivated the increased speed of pc3200 and dual channel mode. After saving, I returned and reactivated SPD (an option other than Auto; I am not sure what the acronym stands for). Since, the pc has run all night without a hitch, and I even see the increased performance of the extra 512mb, moving from PC2100 to PC3200, and dual channel mode. Again, Kingston's site says they do not suppot my motherboard (Asus A7N8x-Deluxe (non-E version); I wish someone could shed some light as to whether or not it means the ram WILL NOT work correctly or they simply refuse to support this mobo. Thanks for your time and help!