WMV2 Conversion

Hi everyone,
I’ve spent almost an entire day trying to convert a video that uses the WMV2 codec (15 FPS) to something more accessible like H.264. I’m also trying to replace the audio track with a separate audio file that I recorded (which is why I haven’t just used Flash Media Encoder, since I didn’t want to have to deal with audio sync issues).

So far, the best luck I’ve had has come by using [w]MediaCoder[/w], but the resulting files (I’ve tried H.264, MPEG4, MPEG2, and H.263) are longer than the original video (34 minutes vs. 25 minutes) so the video and audio are slow.

I don’t have enough experience with video conversion to figure out what’s going on, so I was hoping that you guys could either suggest alternate programs to use (Windows or OSX) or a way to fix the problem with MediaCoder.

Note: I can’t really re-record the video, so I am stuck with WMV for the source video.

Thanks for any input!

Edit: I could probably even be satisfied by being able to remove the original audio track and add the new track and end up with a different WMV file, but I wasn’t having luck with Windows Media Encoder either.