i have an ibook g4, and was using it just fine the other night, then when i came back to it a few minutes later it had shut off completely. now when i boot up, the computer freezes at the spinning gear startup screen or at the blank blue screen immediately after the spinning gear. it will boot in single user mode, but it won't boot up with my os x install disc. does anyone know any unix i could try to use to get my mac up and running again, or has anyone had this same problem and knows a fix for it? thanks for your help