Comment 25 for bug 436792

Please try updating again. The incompatible protocol problem should be resolved now - upstream had a bug (Bug #440807), but it was not known at the time that we'd done a nightly snapshot.

As for pulse audio, it was actually first introduced to Ubuntu in 8.04. Not many are happy with how the transition is going, but it appears to be the (much needed) future path of Linux audio.