I have a Power Mac 7600 and I am using a Samsung adapter to connect my Samsung SyncMaster 793MB CRT monitor to it. The top part of the screen, where the menu bar is, is distorted so that the menu bar is hard to read. The other 99% of the screen looks fine. Do I need to buy a new adapter? I am using the onboard video. I also tried changing the DIP switch settings to no avail.