Maybe try to convert the DivX audio to MP3 then with VirtualDUB. Load in the AVI file, in Video set to Direct Stream Copy. In Audio set to Full Processing Mode. Then in Audio again, set the Compression to MP3, say at 128bits Stereo 44.1 (or 48 if it is already). Then in File, hit Save AVI, give a NEW name and wait for a while. Then try playing the new AVI.