When the muxing stops part way through, it tends to be a crappy Audio part of the DivX in the first place that DVD2SVCD cant rip out properly. This is a fairly common problem unfortunately.
Just rip the audio out with NanDUB, set Audio to Direct Stream Copy and then Save WAV but name the file as ??????.mp3, not wav. Then use BeSweet to convert the mp3 to mp2 audio. Rename the final file to Encoded_audio_1.mp2, copy to the folder that DVD2SVCD was using (overwrite existing incomplete file), run DVD2SVCD and in the Misc tab select Recover, set to Muxing & Cutting and then Continue. Soon all will be sweet.