GraphEdit: AVI length roughly twice that of original WMV

[ToeCutter]

I've been using GraphEdit for a awhile now to extract AVIs from WMV files and I've run across something a little strange.

I've just extracted an AVI from a WMV using the method described here at VCDHelp's FAQ. I used both the AVI Mux and File Writer filters to write the stream to an AVI. When I play the AVI, it shows a running time that is roughly twice that of the original file (9:42 vs. 19:27).

Is this an issue with the AVI file or WMP (which I'm using to view the AVI file)? I suspect (and am hoping) that WMP is calculating the running time incorrectly.

I'm deathly afraid of running into audio sync issues, despite encoding audio and video separately and muxing them later.

[ToeCutter]

Does anyone actually respond to posts on this forum?

I guess the wrong timestamp is due to the variable framerate that WMVs employ. That's the only logical explaination I've been able to come up with. That assumption leads me to yet another question:

What happens when this AVI is encoded in MPEG2? Can the encoder correctly encode an AVI to reflect the original running time?