Audio engine won't restart after it stops

[DavidLight]

I have a few projects that will permanently lock up the audio engine when anything stops it (until a forced restart of Cakewalk is done).  The audio engine button will not start it back and the dreaded "program is not responding" message will come up for a while.  So far this has happened in projects that I have used Melodyne in even after all clips using Melodyne are rendered.  In these projects even "bounce to clips" can cause an audio engine stop.

I was reluctant to post this since I don't have a solid recipe to repro.  I was wondering if anyone else was seeing this.