Hi, I updated my PowerBook G4 to 10.5.1 and now Mail won't open. The blue light in the dock shows up, and Mail's menu bar shows up but is unresponsive. A few seconds later, it crashes or "unexpectedly quits." Please help me, I don't know what to do. Mail is very important to me because my university mail goes straight there, and I no longer have access to all my mail via the website. Thanks!!