I purchased a refurbished 1.33 GHz 15" PowerBook a few weeks ago, and I can not figure out what revision it is!! All the sites I see comment on the 1GHz 1.25 GHz 15" PB, then skip to the 1.5, 1.67 GHz PBs. . . Is the 1.33 GHz 15" PB like a revision and a half or what? Just curious, I need to upgrade my sig from my old 12" that I have sold! Thanks!!