I remember it was quite tricky getting dust to work, as it's a filter for Avisynth 2.0 which hasn't been updated for 2.5. I think I used the method described on this page.

Isn't scenalyzer more suited to DV capture? What capture device are you actually using? If it's something like a ADVC-100, then you won't be able to capture with huffyuv.
:: Edit - OK I just looked back at your previous posts, and you indeed using a DV capture device.

Keep in mind that what works for me isn't necessarily best for your situation.

If you get dust installed correctly, just insert a simple

PixieDust()

command before LimitedSharpen().