John, you said it was just as I described. Did you try removing the Guide Simulator from the Simulators profile or connecting to an already running INDIServer. Did it not crash under these conditions as I found? Also you noted that it didn't happen in 3.5.4, I think I downloaded the old DMG for 3.5.4 and tested it in my experiments yesterday and I think it crashed for me. I will have to go back and try that again.
I guess the next question is what is different about my computer and John's computer vs. Simon's and Ryan's computer. And the next question is why didn't this happen in the past but seems to happen now, what changed? It is mysterious.