This:
-According to the "properties" of the video file in Womble, the video is of the "ffdshow Video Codec" format. I have ffdshow installed, so it sounds like it should work.
is confusing. I think that Womble is reporting that the video is being decoded by ffdshow, but it doesn't actually know what codec is used for the video encoding.
I suggest you try and find out more details about the file - load it into VirtualDub, or try GSpot/MediaInfo on it.