PortAudio is really just a uniform layer over APIs which already exist on the platform, so any synchronization problems those APIs have will be reflected in PortAudio. I did some reading about this in the portaudio newsgroups, and synchronization seems to be a difficult issue to solve.
I'll research this more and add synchronization samples to the bindings project as I figure things out. FMOD and BASS are good libraries too! :)
