image/audio synchronization

[robert langdon]

I have uploaded a MPEG4 file without any problems, having said that, there is a delay between image and sound.
How could that get fixed easily?
I tried reading the other posts which suggest consulting the troubleshooting section but, I can't seem to find that option on the version of the Apple TV converter that I run. Presumably I will have to get the newer version
But, I wonder if there is there another way?
Shall I upload the MPEG4 again?
Many thanks for your help,
Robert