I'm getting occasional jaggies and black lines one the bottom half of the screen, almost like bad interlacing, from my DirecTivo (capable only of 720P/1080i) to my 990 to my TV (Pioneer 50" plasma) over HDMI-DVI and DVI-HDMI. It's not all the time by any stretch, but I can recreate it with any white or light background. It's almost constant watching hockey for instance. The black lines on the bottom half sometimes look like a jagged "ghost" of the top half of the screen, like an interlaced overlay. This happens in both 720P and 1080i. Native resolution of the screen is 1368x768.

I would say it's the display but I can watch DVDs of hockey (or anything else) all day and always have a perfect picture. I can also hook up my DirecTivo to another display (Panasonic 50" plasma) over HDMI and not see any anomalies.

The cables check out fine on other screens and I've swapped through multiple brands all with the same issue. Cable length is 2 3' lengths. 3' from DirectTivo to 990 and 3' from 990 to TV.