Decrypt your DVD to your hard drive using DVD Decrypter then try Auto Gordian Knot (a bit of a mouthfull I'll admit)
It's excellent. Just make sure you select CBR in the Advanced section for the audio and choose a sensible size for the video (about 200 meg per half hour of video seems ok for the quality GP32 needs). It runs two video passes and an audio pass. The resulting file is easily converted into GP format with Virtual Dub. I've encoded two series of Red Dwarf so far and the results are great at about 35meg per episode and 17FPS.