when working through the 'midi processing' tutorial I managed to get the presets "M4L.md.09.Feedback" and "M4L.md.10.Arpeggiate" stuck in infinite loops so that even if I turned down the feedback control the notes kept playing. Also the other controls dont affect the play back.
another problem with these patches is the part of the interface labelled "MIDI from Live" actually shows the output from the patch, because it is part of the feedback loop. I guess its not that important but might confuse new MAX users?