Will the Firefox plug-in "DownloadHelper" convert videos to use with Sansa Fuze?

I installed the plug-in and it’s really an awesome one.  But seems that no matter what format I convert the videos to, they won’t play on the Fuze.

Do I _ ABSOLUTELY HAVE _ to use the Sansa Media Converter _ OR _ can I convert the videos using a utility like DownloadHelper?

You have to have Sansa media Converter for right now.