AVI input problems in AutoGK

[quake74]

Hi all, I'm having problems with the AVI input feature of AutoGK. I am trying to convert a screencast (captured with camstudio using Xvid) but it's really slow.
I mean, the screencast is a 40Mb file of about 5 minutes and 20 secs, but virtualdub says it will take it 30 mins to analyze, and the total time is still increasing. I am on a Pentium M laptop, but this is 10x slower the speeds I get converting DVD's. I know decoding MPEG4 video is harder that MPEG2, but 10x? And why does it say it's 200fps?

Partial log follows:

7/17/2005 1:31:39 PM] AutoGK 2.13b
[7/17/2005 1:31:39 PM] OS: WinXP (5.1.2600).2
[7/17/2005 1:31:39 PM] Job started.
[7/17/2005 1:31:39 PM] Input file: recursivescreencast.avi
[7/17/2005 1:31:39 PM] Input codec: XviD
[7/17/2005 1:31:39 PM] Source duration: 5mn 19s 620ms
[7/17/2005 1:31:39 PM] Output file: D:\recursivescreencast_agk.avi
[7/17/2005 1:31:39 PM] Output codec: XviD
[7/17/2005 1:31:39 PM] Subtitles: none
[7/17/2005 1:31:39 PM] Format: .AVI
[7/17/2005 1:31:39 PM] Target size: 20Mb
[7/17/2005 1:31:39 PM] Custom resolution settings: fixed width of 640 pixels
[7/17/2005 1:31:39 PM] Started encoding.
[7/17/2005 1:31:39 PM] Source resolution: 800x600
[7/17/2005 1:31:39 PM] Source fps: 200
[7/17/2005 1:31:39 PM] Analyzing source.

[quake74]

Maybe it's bad etiquette to auto replay ;) Anyway, actually the file was really 200fps and that is why (adding the fact that to decode the avi ffmpeg was launched) it was so damn slow. So i reduce the number of screens per second and it's much faster, very acceptable. However, now although AutoGK determines the correct fps of the files, after the conversion, the video part is about 3x faster that the audio. I also tried setting it manually in the .fps files, but to no avail. Guesses for solutions?