Same problem here, see my posts on this forum. My equipment include a Sony AV receiver, a Panasonic HDTV. My ATV was first connected to the receiver thru and XtrmeMac HDMI switch which I took off thinking it may be the cause, and connected directly thru the receiver. Just the mere fact of switching HDMI will render the screen black (no signal form ATV). MY ATV is version first gen version 1 and has worked fine thru all upgrades until 3/3.01. This has been very frustrating and the only solution I can come up with is to fashion an easy way to power ATV off and on after each use. I am hoping for a quick reliable fix for this disastrous upgrade form apple.