The reason I needed to remove it is that clicking on a .m3u loaded the Quicktime in-browser plugin, rather than loading the file with the external Winamp player.
Basically, you have to remove any file named these from your system:
You have to remove several versions of this. If you still don't have all of them removed, use procexp to list the .dll's loaded by your browser, and to find the directory of the remaining version.