I recently purchased a new Memory stick.. believeing that it would be compatible with the memory I currently have.. This is what it says on the older mem stick : "512mb 64X64 PC3200 CL2.5 DDR" now my system Bios states it's running it at 400mhz at 2.65v okay, The stick I just recieved in the mail is a 512MB 184-Pin DDR SDRAM DDR 400 (PC 3200)next with each mem stick in "solo" - Dimm1 Windows Memory Diagnostics checks out great!! no failures.. when I attempt to put them in Dimm1 & Dimm2 and run windows Mem Diag. it freezes up?? now the two things I find odd are: 1. my old stick states 64X64 which I have no clue what that means. & 2. One stick has mem buffers on both sides and the other only has mem buffers on one side?? Any helpfull advice on this would be greatly appreciated! Mainly just want to know if this new stick is even going to be able to work for me..?