*doesn't talk at all about how xine plays DVDs and divx and pretty much every other format of video I can think of just fine, and how all you need to do to install it and all its dependencies and codecs in gentoo is type "emerge xine-ui" and wait*

Did TweakUI work? I never had good experience with autoplaying CDs in Windows. Usually I just give up with trying to configure anything, hold down SHIFT while the CD first gets read (holding down SHIFT overrides any auto-playing of CDs, generally) and then open it up in Explorer.