I've got the progress bars working again, woot!.

They where broken when I brought in multi-threaded rendering for the animations.
I've since added code to multi-thread the stills rendering which broke those
progress bars too. So after painting myself into a corner I really had to find the problem which was...

The new code was blocking the main thread, where all the drawing takes place. D'oh!

I've had to move the rendering code into a another thread. Its had some side effects though as there appears to be other things that 'prefer' being run in the main thread, NSSavePanel for example . There's probably memory issues too, stuff allocated in the main thread that gets auto-released before the new thread gets to use it. I've got some fun ahead moving code around, and getting it all working nicely before closing the bug on SourceForge.