Couchdb loads its own internal server. Whenever it launches you are unable to debug MonoTouch projects. You can run the attached sample in debug mode and the debugger fails. If you run the app it works great.
it looks like couchdb is closing the socket connection between MonoDevelop and the app, probably when it forks off the server.
MonoDevelop can't override CouchDB closing socket descriptors in the app.
I haven't closed this bug yet because I'm trying to think of ways that MonoTouch could prevent CouchDB from going behind its back and closing socket descriptors, but I haven't thought of any way to do that yet...
Speaking of which, I should reassign this to the MonoTouch team as it's clearly impossible to workaround in MonoDevelop.