Added a second DDR2 DIMM to my PC. It now hangs on boot - sometimes I get 3 beeps on start up, but usually just a black screen. Sometimes I can hear the hard-drive cycling (clicking) but not booting. I have a single 1GB DDR2 in DIMM socket A0. The new memory is in B0. I have tried the new memory in A1 and B1 with the same result. When I remove the new memory my system is fine. Is this just a case of bad memory right out of the box?
Intel MOBO - 945PVS
Intel Pentium D840
1GB OCZ 533MHZ RAM (in socket A0)
Seagate 250GB ATA 100 HD