I recently ordered and received a 17" PowerBook 1.33 Ghz. It's a great machine, but It won't accept any DVD's I put into it. It sounds like it is trying to read, but just spits it back out after trying to read it for 10 seconds. It accepts and loads my CD's without a problem but even after 5 or 6 trys it still spits out my DVD's. My computer teacher has a 15" PowerBook and she doesn't have any troubles playing DVD's. I'd like to know what I should do.