As I said, it is an early build and the whole thing was first made only for me, but..
There are two things I see could cause the problem.. you wanted to convert a unsupported media format(it should be a MKV with h264/AC3 inside) or the mediainfo is causing problems, since I think I bundled the x64 version with this.. so please try to replace the mediainfo.dll with the win32
here
Keep me posted on the results.