I bought a Samsung 160 GB 5400 rpm laptop ATA hard drive to replace the stock 4200 rpm 40 GB that came with the first generation 1.25 GHz G4 mini. I disassembled the machine and put in the new disk and the problems began. The mini will no longer boot from the Leopard install DVD. It just doesn't find it. I reset the PRAM, didn't help. Held the option button during startup, doesn't find any bootable drives. So I pop the stock hard drive in and everything starts working just fine. It boots from it or from the Leopard install DVD. I pretty sure I installed the new disk in properly. Is there anything I can do or is that new Samsung just incompatible? edit: Disregard the thread. Solved it. I guess the disk has to be plugged in all the way, not even a 0.5 mm gap.