I captured a mini DV footage via Premiere 6.5, loaded up in FitCD and chose 544x576, when trying to load up in Vdub, it gives me the following message:

Avisynth open failure:
AVISource:couldn't locate a decompressor for fourcc dvsd

How do I fix this problem, thanks in advance!

I had the same problem. You apparently don't have the codec for this avi. Seems as though there are hundreds of codecs for avis. You got to have the correct one.

In my case, the ReluctantAstronaut.avi was a Type 2 DV AVI and its associated FOURCC codec is "dvsd". On such dvsd codec is the MainConcept DV codec. Without the codec, my avi would load into TMPGEnc and WMP, but not Virtual Dub or work with Avisynth scripts. By installing the codec, it should work.

Some interesting sites are www.moviecodec.com and www.fourcc.org. You can get the correct FourCC code from these sites. Simply download and install.