movie maker capture = corrupted AVI

I have captured a DV video from camcorder Sony TRV8 with Movie Maker 2.
The captured AVI (about 12GB) playes flawlessly within movie maker and with
windows media player 9.

Unfortunatelly when converting the AVI troubles arise: the audio extracted
track plays "crazy" either is sampled incorrectly either it is sampled
correctly but plays faster then exptected at the beginning of the track,
slowing down progressively to to the end of the file.
I've tried the audioaxtraction with tmpgenc built in engin, with toolame or
with adobe audition, still the sam problem.

I've tried wit the latest version of Gspot that states:

"This is an invalid AVI file due to corruption of the data in the header.
This is a serious problem, and this file is not likely to playable
Details: While processing chunk /RIFF:AVI , found bad length value
1069516804 at file offset 0x00007ff8"

I've tried to capture the video again two times, same problem.

The AVI is a "type-1".

What's the problem?

Another funny behaviour: I've also tried to capture the video from DV
camcorder with videostudio 7 but the output (even if forced to "type 1") is
smaller (9GB) and juggy with same frozen frames; also while capturing the
CPU is envolved at 50%; while using Movie Maker the CPU hardly reaches
3%......

Help!!!