Unfortunately I think the resolution is an issue here. I've hooked up the RGC via variant 1 (dvi>hdmi) and used my TV as the monitor. When I start the source PC with this configuration, it works, but Windows XP will limit the available desktop resolutions to 800x600, 1152x648 and 1920x720.
I've tested two games.
1. Dune 2000: The original ingame resolution is 640x400 16:10. At first I get a disoriented image, after I start the game. (Might be the transition from the windows desktop to ingame). When I reselect the source, I see a stable image, but it got resized to 720x480 4:3.
2. 1602 A.D.: Ingame I can choose between three resolution modes 640x480, 800x600 and 1024x768. 800x600 kinda works. The captured footage has a resolution of 1920x720 4:3 and the game screen is somehow centered in this frame. In 640x480 the image is screwed and selecting 1024x768 will prompt an error message on the source PC.