Here is a list of some HDMI issues that we have seen.
HD mode not being set automatically
In some cases, the auto detection for HDMI may not be working perfectly with your TV. Try setting your HD resolution manually by pressing the setup button and then choosing Display -> Display Settings -> High Definition (HDTV) and then choosing the 720p, 1080i or 1080p setting.
On some TV's, the HDMI does not get reset properly on a soft power up. This usually happens only during a brief period after start up.
Another green screen related issue is due to some HDMI TV's not supporting PAL timing. The green screen would happen while in the setup menu in this case, but be OK during normal viewing in HD mode. There will be a firmware update to address this in the near future.
If your setup screens are green, you can fix this issue by pressing setup on the remote, and then choosing Display->Settings->High Definition and choosing the NTSC 480p setting. After you do this, the setup screens should not be green. You can then choose a 720p or 1080 setting again so that you can connect to the server in HD mode.