I decided to go ahead and remove totem (don't much care for it anyway), and when I double-click a sound file in nautilus, it runs mplayer to play the file, but I also get an error window (from mplayer) that says "[AO OSS] audio_setup: Can't open audio device /dev/dsp: Device or resource busy" but it is playing the sound file just fine. I can close the error window and everything works; if I close mplayer instead, both mplayer and the error window disappear.
What gives?