Update: It looks like this issue will be resolved in the iOS 4.3 update. Currently, beta 2 has an option to change the HDMI mode. Switching the mode to RGB High prevents the display issue from occurring.
Over the holidays, I was lucky enough to receive a Sony Bravia KDL-32EX401 TV as a gift. I'm finally able ditch my old Bush HDTV, with it's wacky array of non-HDMI ports.
This has reduced clutter behind my set, as I can now use a single HDMI cable instead of all the cables I previously used to work around the Bush TV's lack of HDMI.
The Sony TV is wonderful - the picture is great and the TV firmware is actually quite usable. It's also upgradable via USB, which is a nice touch.
Unfortunately, I've encountered a serious display issue with the Apple TV when it's hooked up to the Sony TV. The display randomly flickers and the colours become inverted (see image below). The only way to resolve the issue is to switch the HDMI input source and back again. This is infuriating when watching a movie or TV show.
I've reported the issue to Apple over on their bug tracker - the bug has been closed as a duplicate of issue #8511726.
There are a number of other users reporting the same issue over at the Apple Discussion Forums. The problem seems to be spread across a number of different manufacturers and models.
If you are seeing this issue, please report it to Apple customer care, or better yet, file a bug report at Apple's bug tracking system (you may need to sign up as a developer to do so - it's free to register). The more users who report the issue, the higher the probability of Apple providing a fix for this quickly.
Hopefully Apple can resolve this issue ASAP. Until then, I'll be searching for a workaround…