I have a VCR hooked up (but get the same results when I hook up a PlayStation 2), and the image is semi-viewable, so it's not completely messed up but definitely not watchable. When I bring up the OSD menu, it says it's displaying 679 x 559 at 50Hz.
I reset to factory settings to no avail, and there is no option to explicitly set the Hz of the incoming signal. The odd part is that this worked fine 1 month ago, but I had unplugged everything since and reconnected everything today.