I recently purchased a Slingbox and SlingCatcher and installed the SlingBox at my parents house in the U.K. I'm now trying to watch the output using the SlingCatcher I have connected to my U.S. television. Is the "mode not supported" message similar to the problem with DVD players from the U.K. being a different region from those DVD players from the U.S.? If anyone can help me with a workaround, I'd appreciate it.
It seems that you are having some issues with the SlingCatcher since it shows you the "Mode not supported" error message.
This issue is related to the resolution of the TV source (cable box, DVR or satellite receiver). With this in mind, I recommend you to downgrade the resolution and test it out. Let us know how it works for you.