Frederik,
I came across this odd NodeBox bug the other day. If you set your document size to 700 wide by 525 tall (or apparently any width at 525 tall) and try to save a movie, the movie will fail to finish converting. The result is a zero-byte mp4 file that Qucktime cannot even open.
Setting the document height to anything other than 525 solves this problem. Took an hour of hair-pulling to figure this out when I was trying to produce an animation on a deadline.
Sample Nodebox file and zero-byte movie attached. For the demo file I just made a simple orbiting circle. It doesn't seem to matter what the content is. The only thing that matters is the 525 document height.
I'm guessing this may be an easy fix. Thanks in advance for looking into it.
John