Hi James,
Thanks for the explanation. I realized it was probably % complete shortly after posting this.
However, I should be clear, it definitely *is* the case that the first 100 frames are being rendered successfully . I rendered a 280 frame animation to prove it, but it gets stuck after rendering the first 100 frames (hence why I made the mistake of thinking the log was recording frames synced).
Is this because the first 100 are being stored in the primary blend, and the others are getting written to cache files? Did you happen to try out the .blend I posted in the issue tracker?
Cheers,
Lawson