dell shipped a 64mb stick of toshiba PC-125(so sais sisoft sandra) with infineon chips( i looked at the sticker, i am assuming it's the 64 mb stick because it's larger)
and a 32mb stick of Siemens ram. haven't had any problems with them.
and sandra also sais both of them can run at CL2 at 100mhz bus, and the toshiba can run at 125mhz at CL3... didn't know that. unfortunatly with dell's bios i have no way of changing it, so i guess i'm stuck at whatever they set it at