The lockup sequence works like this for me.
ANY film selected from Film on the clipboard and run full screen on the FE.
ANY film double clicked from the Film folder and auto activating the Film viewer.
However, if I launch the film viewer and then select the film from the Films menu, they *usually* play to completion (as long as I don't mess with any of the controls along the right edge of the window... changing viewpoints etc. does not seem to cause a lockup, but trying to FF via the slider will.)
Dwarf