Interesting .... I have some Dreamcast rips but never could actually play the games since the video display of the games never displays properly. For instance, with Sonic, I can see the little dude run around and jump, but the background image or cards and such are not displayed. Also, with a fighting game (forgetthe name), then background images are not visible, just the two people in the fight, however, the image of the people fighting are not nicely drawn either.
People told me that it was because I was using onboard video and Chankast does not really like this somewhat.
Are the "errors" you refer to similiar to what I am experiencing? I mean if I try to use Alcohol120 instead of Daemon tools, then will the game work .. perhaps?