I couldn't get Popcorn 3 to launch with mac OSX 10.3.9 - just bounced in the dock then disappeared - so upgraded to Leopard and it still won't work. I emailed Roxio support twice over the past 3 weeks as I'm based in Australia and no-one has returned my emails - very frustrating and bad customer service whatever the problem/solution is.
This update better work whenever it's released . . .