Hi, i have a G4 Quick silver (733 mhz with 1GB ram) i installed leopard on it using the firmware cheat to let it install with a 733 processor, this worked fine and ran really well for 4 months. Last week it kept crashing (power logo on screen with message "you need to restart your computer") i tried resetting the PRAM and repairing permissions but this did not help (Kept crashing during permission repair) then it died and was stuck on the apple logo startup screen. I have 10.1(came with mac originaly), Tiger and leopard (both black retail) DVDs so tried reinstalling Leopard, this started to work then failed at the last little bit of the blue bar on the main install, I tried again and it would not see my harddrive, I erased the disk with disk utility and it saw the drive again but needed Tiger installing before leopard, this took about 10 tries (failing at different points each time), when it finally worked i tried leopard with the firmware cheat (cheat worked fine as installation started ok) this failed a few times then seemed to finish installation but got stuck on the apple screen when restarted, and wiped tiger off the mac (or would not start with Tiger) I am now running ok on tiger although trying the system update does not work (freezes) I really need to be running leopard for my iphone etc. I hope i have given enough info for someone to help if possible thanks, Jake P.s i have tried disk utility to repair disk n permissions and it says its all ok. I think i have tried everything, could this be a hardware problem or would the disk repair show that?