If you're trying to use the Fink install of esound, you may get an error about an 'unsupported device' at some point. According to a post by SinceWhen in this thread on the forum site, the fix may be as simple as changing a setting in (I believe) Audio MIDI Setup (in Applications -> Utiltiies). From SinceWhen's post:
... I went to my MIDI setup and I discovered that my Output Line device was set to 48000 Hz. I had no idea how it flipped. I changed it back to 44100 and everything ran smooth!I can't confirm this one, as I'm not using esound, but thought it was worth sharing.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20041104054721974