I have an AlBook 867 mhz 12 in powerbook. While carying it the other day the hard drive made a funny clunking sound. Shortly after it froze bringing me to the gray shut down screen, then again after i rebooted it. Now, programs are opening and running very slowly and if i hold it at an angle, it makes a humming sound, like the disk is rubbing or something. I tried disk first aid, smart is verified and it says the drive is ok, tho it took it about 5 mins to check the drive. Do i need to replace it?