I spent a lot of time trying to make a Matrox G400 card work in my Mythbox (30.2 release) before giving up and trying a GeForce FX5200. I'm using a Viewsonic VG150 LCD monitor, and when I booted the setup CD with the command line

knoppmyth tv expert

the screen went blank, though the PC continued to boot (or seemed to). I had to specify the resolution (800x600) bit depth (16) and hsync (72 Hz) before I could boot and see the setup screens. Is this normal behavior?

Also, when installing I specified a desktop of 1024x768 and told MythTV I wanted 800x600 resolution during setup. When I'm looking at the X desktop (with the KnoppMyth graphic for desktop wallpaper), the top 1/2 inch of the picture is rolled around to the bottom of the screen and you can see the tops of the letters for "KnoppMyth" in that area. Between what is the normal bottom of the screen and that rolled part of the top is a black area that looks like it might be a command line area. This is definitely not normal behavior. Should I specify a higher (or lower) refresh rate to center the picture, and if so, what setup file holds that info?

LCD monitors are often very particular about the signal you given them. Read the manufacturers documentation and use the Horz. and Vert. refresh rates they recommend at the resolution they recommend and you'll be much happier.