is this why conversion is taking 20+ hours?

[wittypseudonym]

TMPGEnc would not load the audio part of my .avi file, so I tried using virtualdub to convert to .wav. I did everything as per the guide, but got a message referring to the source being incompatible. I tried again, NOT changing to full processing mode this time, and the file was saved. TMPGEnc loaded this file ok, and conversion started ok, but is now 6 hours in and moving REALLY slowly.
Looking at the properties of the original .avi file, the audio format is 'unknown format'. Is this causing my time troubles? Am I missing something that will recognise the audio format?
The .avi plays (with audio) no problems at all, as do sample conversions.
Please help!!

[sommersby]

did you install the vfapi in tmpenc?