I have a G4 Powerbook 1.5ghz 15". It takes PC2700 RAM. I bought some RAM from ebay: SODIMM 1GB PC2700 1G DDR SDRAM 333MHZ 200pin LAPTOP RAM Standard 200-Pin PC2700 333MHz NON-ECC DDR-SDRAM SODIMM DDR-333 PC2700 128Mx64 Latency CL 2.5 Voltage 2.5V When this new stick is in the slot, the machine reports that slot as being empty. Another stick works fine in the slot (it's the upper slot so I know it's not the lower slot issue that these machines sometimes have, anyway). Now, did I screw up and buy the wrong RAM (quite possible), or is this stick just a dud?