MP3 player not fully recognized since upgrade

I have a Creative Zen Nano Plus. It is a regular mass storage flash type player. It worked perfectly under Hardy. When I plug it in it is recognized as an mp3 player, it gets the ipod nano icon on the desktop. When I click on that icon, I am given the choice of opening it in Rhythmbox. When I choose to do that, the music currently playing in Rhythmbox pauses (rb used to stop playing whatever was on and autoplay from the device when I plugged it in, which is an annoying stupid feature), and the files on the device are imported, but nothing pops up in the side pane that I can drag and drop to or use to eject the player. This previously worked in Hardy and probably many releases before that. I tried to throw in an .is_media_player file but that didn't help. I have both the ipod and mtp plugins installed, though it shouldn't need either.