Hey guys, my professor's powerbook is going kinda funky right now. It's consistently reverting back to 640 * 480 resolution. How do we fix this? I went to display preferences and changed it to 1280*1024 resolution. However, there are black lines along the sides as if it isn't the right resolution. What's the default resolution for powerbook 15"? *It also seems to revert back to 640*480 after a few seconds but that might just be because we forgot to click "confirm."