PD6 - continually looses coherence

PD6 continually drops out of coherence to a Windowed mode. Also if I minimise a Windows Application, how on earth do I bring the window back up? It's not in my dock! Other bugs - in coherence I have a grey square just sitting on my mac desktop. Occasionally I cannot bring a windows app in front of a MAC application by clicking on it. Also, I liked that I could suspend the VM by cmd+w in PD5. And resuming from a suspended vm takes a lot longer now. 3 days of my trial left, not finding any justification to move from PD5 I'm afraid.