Everyone, I had the green screen issue as well and I was able to fix it using the menu. Here is the help I got:
Moto 6412 Phase 3 into the H78 DC3 via HDMI/DVI:
I'd suggest checking the settings on the Motorola box itself. If you press 'Menu' on the remote while the box is off you get the internal settings. There you will find additional HDMI settings (Press the right arrow on the remote). There is an HDMI/DVI mode setting as well as a color space. Make sure its set to DVI and try playing with the color space (toggles between RBG and YCC 4:4:4)I changed the color space to YCC 4:4:4 and it worked.
Note: the advanced settings only come up when the HDMI is plugged in.
Other useful info:
I'm using 1080i on the HDMI/YPbPr and 480i on the 4:3 override. You may want to play around with 1080i/720p. Most HD channels are broadcast 1080i. On a 720p display it becomes a matter of which device do you think does the better job of scaling. If you think its the Moto, choose 720p. If you think its your display choose 1080i.
OFF displays non-HD programs having 4:3 aspect ratio in wide screen format. On an HDTV, black bars display on the left and right of the picture. Selecting OFF for a 4:3 TV may result in a small picture with black bars around it.
480i displays non-HD programs in their original 480i format.
480p converts non-HD TV programs to a higher quality 480p
Stretch automatically stretches all SD programming to fill your widescreen display. Strech can onlt be selected if you have TV Type set to 16:9
I have a optoma H78 and got these instructions as well:
If you choose 720p on the moto, it will pass 720p (basically the espns and abc) and it will scale 1080i to 720p. The optoma is receiving 720p so it shouldn't have to do anything.
If you choose 1080i on the moto, it will scale 720p up to 1080i and it will pass 1080i. The optoma will scale 1080i (essentially everything) down to 720p for display.
Since the majority of stuff is 1080i, choosing 1080i has the motorola scaling less (unless of course you primarily watch espn/espn2/abc).
Regardless of what type of signal the Optoma is getting, it can only display it in its native 1280x720 and it will up/down scale as necessary.
I'd try 480i on the 4:3 override as the Optoma will also scale it to 720p for display.
Let me know if any of this helps!