Ever since I upgraded my system software (10.5.6) and iTunes to 8.1 on my Powerbook G4, I've been having problems with iTunes. The music cuts out and the songs stall. Is the systems software too bulking for a Powerbook G4? I tried reverting to and older version of iTunes, but the same problem kept occurring. I thought it might be the file type, so I switch from MP3 to AAC, but nothing different. Any solutions would be welcome.