Audio delays while converting, can someone help me??

I am using videora ipod converter to help me convert avi. files to mp4. files for my ipod. As an avi file the movie will work perfectly but after being converted about after 45 minutes in the audio start getting delayed.

Like i’ll see the persons mouth moving and then 2 seconds later ill hear his voice? I tried a few different movies and they all do this

Can anyone help me??

Thanks!!!!