When I purchased my 6000 receiver, the salesman asked whether I have the Toshiba RPTV for they are known to have the mentioned problem. Hope you got the fix from Toshiba.
Back to the original questions. If I don't have a HD ready TV right now and I am in no rush to buy a TV, I won't go into HDTV. There ain't that many HD programmes. As mentioned there are only 2 free + 1 PPV channels. For the PPV and the movie channels, you can't watch Gladiator, Frequency...
Dean, I just got my 6000 a week ago. If you go into the HDTV setup (within installation), there is a button labelled as ADJUST. If you click on it, you can adjust the location of the pictures within your TV.
I think 720p has higher resolution than 1080i (720p uses higher freq). So it would be downconvert from 720p to 1080i but right now most HDTV are running at 1080i.
About 2 weeks ago, a speaker installer was setting up the surround speaker setup for me, while doing so he also changed my TV settings. He has the sharpness at 10 but since then I have increased it to 40. The rest are: contrast 45, brightness 50, color 50, tint -5, sharpness 40, fleshtone off...