To record Windows Media streams I prefer to use
WM Recorder or freeware
WebVideoCap.
All Windows Media streams that you record are actually .ASF files. However if these .ASF files have .WMV or .WMA extension, it doesn't seem to make any difference for any player supporting Windows Media format.
WM Recorder can automatically index .ASF files, so you don't have problems fast forwarding them. You may also use other
software to make .ASF files seekable.
You may need to index .ASF files first (make the seekable) before converting. If it doesn't help, please upload the file to some file sharing web-site like drop.io and post or pm me the link, so that we can try to solve this problem.
p.s.
Replay Media Catcher and
WM Recorder have a 30-day unconditional money-back guarantee, so you have nothing to worry about.