Compatibility between different HDMI devices can be a crap shoot sometimes. While most devices will work with each other without ever any any issues, various devices may have different ranges in cable length that are effective and some devices won't work in certain combinations. For instance, some receivers or switches will work with a PS3 to one TV but not another, or not another if you exceed a certain length of cable or use too thin a cable. Report your findings here. What set ups, including makes and models and cables being used have you had success with and which combinations did you find didn't work. Sometimes you'll find a particular setup may work at 720p but not 1080p or visa versa. Let us know so that you and others can benefit from different findings.

Sounds like this may be a good sticky post.