My 1.25ghz aluminum PowerBook is having problems. Last week the hard drive had errors; Disk Utility reported they could not be repaired and I had to erase the drive. Fortunately, I could read the drive when booting from an external disk so i was able to back it up. Then, a week later, I am again having booting problems. I can usually boot from my external drive, but when I do I usually can't find the internal drive. On top of that, it sometimes reports that it can't find the Airport card and, though it can find the optical drive, it usually reports no disk in that drive even if one is there. I ran a hardware test and everything passed, even the internal drive. Disk Utility says the drive is fine. I upgraded the external drive to system 10.4.7 and it now has no problem finding the Airport card or disks in the optical drive. But on the rare occasions that the internal drive shows up on the desktop, the computer crashes if I try to access it. Will replacing the drive solve these problems -- even though it reports no hardware problems with the drive?