[popcornmix]

AspectRatio not working ?

If you are using test builds, then you should be willing to post a bug report.
You need to describe exactly what you do to provoke the problem.
Mediainfo of the file, a debug enabled log file and possibly a sample file that demonstrates the issue are likely to be needed.

To answer your question - no, there are no known problems with aspect ratio (although from your post it's very hard to guess what your problem is).