The ram you purchased, you need to find out if it's high or low density vs the ram that the computer you have is limited to low or will accept high density ram. It's possible, that you may have purchased a high density stick & the computer will only accept low density. Another suggestion is, it's possible the stick is bad. Try it out on another computer, even a Windows system. That will rule out if the stick is bad. -----Original Message----- From: g4-bounces at listserver.themacintoshguy.com [mailto:g4-bounces at listserver.themacintoshguy.com] On Behalf Of johnnyg Sent: Monday, February 04, 2008 8:04 PM To: G4 at listserver.themacintoshguy.com Subject: [G4] memory problem in dual 867 Hi, I just purchased from OWC a 512 memory chip to put into this newly acquired mirror doors with only one 512 slot taken......however, after installing the memory, I have had freezes kernel panics and other strange attrocities often. I moved the memory about in different slots and tried resetting the pram, and pma. No help so I removed the memory and everything is smooth once again. Is there some magic I should put into service here or do I likely have a bad memory chip? OSX10.39. Thanks. John _______________________________________________ G4 mailing list G4 at listserver.themacintoshguy.com http://listserver.themacintoshguy.com/mailman/listinfo/g4