I have a 15" PowerBook G4 that originallyhad 1G of RAM...so naturaly i wantede to upgrade it so i bought another gig today, but when i went to install i realized that apple used BOTH slots for 2 512gig cards! Now i probably should have known this but i was wondering if anyone has run into this prob, and then gone back to the apple store and traded both 512's for a 1G card? the book is only about a week old...so lemme know