renaming the dll name will only have a possible affect in the loading order when you're using a NTFS based filesystem (standard for XP i believe) otherwise it comes down to plugin file creation and modification dates.
one way to work around the issue is to go through the other plugins which you have installed and remove any unwanted file associations (usually from going to those input plugins and unchecking/removing entries in their extension lists).
you can view what's in the 'All supported types' part by following the instructions from http://www.nunzioweb.com/daz/playlist_loader.html#All_supported_types_Issue.
Just as a thought but since this seems to be an issue for a number of people, it may be possible for me to add to that plugin (or possibly split it out) and allow for the file extensions which go past the 260 char limit to be added into an extra 'All supported types (cut-off)' entry but that's probably not the best way to do it but it's a possible option (since renaming plugin dlls isn't a great solution as explained at the start of my post)