A new external projector in the lecture hall at my school appears to be incompatible with my tc1100. Everything is fine when I first connect, mirroring the displays, but after 15 minutes the projected external display loses sync and starts "jumping around" on the screen. Eventually it goes out of sync altogether and the projector stops displaying anything but "out-of-range" messages.

Has anyone had similar problems? I thought the problem might be due to trying to drive a long cable, but my AV folks tell me there is a video distribution amplifier in the podium to drive the long cable. My problem is NOT with that amplifier, however; it was there with the previous projector and then everything worked fine.