I was trying to make a DVD from 25 .mp4 files with a total size of 7GB. I
added them (each as an own title) and hit "Adjust disc usage".
It started to convert the file just fine and finally produced an image with a
size of 14.3GB.

I read that it's a known "non-bug" that DeVeDe produces images that are smaller
than the precalculated size, but I think producing a larger image should be
considered a bug.

Regards
Sven