I have a 1.5Ghz 15" Powerbook and today the hard drive decided to make a very high frequency squeal. When this happens it also sounds like the drive is trying to read some information and it cant, therefore beachballing every application and forcing me to force reboot it. Sometimes the noise is also accompanied by a grinding noise. Usually after reboot i can get 5 or 10 minutes of use till it starts doing this again. Has anyone heard of any similar problems with powerbook HD's? Does this mean that my drive is failing and that i need to get a new one? When i boot from the Tiger DVD and run the disk utility it usually locks up trying to gather the information. This is after seing if i can even install it on the drive and when i get the window to choose the destination no drive appears. When it was running i ran the disk utility and said everything was fine, obviously everything is not fine.