It sounds like you are right on the edge of compliance with HDMI's cable length, and the extra connections are providing just enough extra resistance to push you over the edge. What other DVI or HDMI sources are you using in your system?
Quote:
I tried various combinations of cables and HDMI to DVI adapters and I sometimes have a good picture at 1080p sometimes not - always 1080i is good.

What combinations gave you a good picture at 1080p?
Quote:
Why would progressive v interlaced make a difference?

Twice the pixels being sent means twice the bandwidth required, which in turn means that there will be less tolerance.
_________________________
gonk
HT Basics | HDMI FAQ | Pics | Remote Files | Art Show
Reviews: Index | 990 | speakers | BDP-93