If your talking about what i think you talking about i had the same problem too. If Virtualdub screwed up i would just create a blank wav file that was the same lenght as the movie and use that instead of the original audio. This of course only works with videos that you dont mind not having sound for. Hope this helps somewhat.
I'm not sure you *have* to use 32k, 11kHz. I wasn't happy with the sound quality at 11kHz, so have just encoded The Italian Job at 22kHz, and I can hear Caine telling me about blowing the bloody doors off just fine
I'm pretty sure the 10 frames per second is a hard limit, and the bit rate for video of 128k may well be too - although I feel a session of testing coming on. But a lot of settings mentioned in the couple of Moviepark FAQs out there are just recommendations.