Hi - My iBook (about 3 years old) all the sudden started continuously restarting. The screen would dim and a black window would appear saying that the computer needs to be restarted with a picture of the power button symbol behind it. I have done that and now the same thing keeps happening every time my computer turns back on. It has happened 4 times in the last 20 minutes. One time as soon as it restarted, it shut itself off as soon as the desktop appeared. Does anyone know what this means? Or how I can fix it? I really appreciate the help!!!!!