either update current add on since we like the playlist option, or need a stand alone jwplayer addon that can be updated later to include a playlist. the reason for using a addon instead of the embed code is the ease of the filemanager.
I assume you have a commercial license for jwplayer since you purchased the add-on originally so I can't see any licensing issues.
First of all, is there a link to a page where your current jwplayer sits? Perhaps we can see where it is storing it's files.
Try to find the package under '[root]/packages/some-jwplayer-like-name' and dig under there for a copy of 'jwplayer.js' and 'player.swf'.
Download the most recent version from here:
Unzip the archive to your local computer and upload only the two files in place of the old files. Don't just over-write the old files because you might need them if the new ones don't work so just rename the existing files to something like 'jwplayer.js.old' and player.swf.old' so you can swap them back if need be.
It's worth a shot if the original developer is unresponsive and your current add-on doesn't work.