By spd means the bios reads the ram and sets the speed accordingly for your pc2700 ram this would be 333mhz so set it to a vaule of 133mhz this will make the ram run at 266mhz the same as your board and cpu. As I said before this is sometimes needed for maximum system stability.
Don't forget to save when you exit.
Try it and see if the problem is fixed.
Rick