I had many problems with my LC-32GD4. Everything was fine with my Philips, but not with Sharp. After one full day of tests : first start AppleTV and then the TV, first start the TV and then AppleTv, reset both of them, changed the HDMI-DVI cable, tried all the possible TV configurations and just few seconds before I was throwing everything out the window it suddenly worked. I don't know why, but it now works.