Hi I have problems with my MOVIE EDIT PRO 2015 PREMIUM

Short videos de audio sincronism is ok but videos beyond 4 minutes the sincronism is not ok. I tryied so many times with windows 7 and now with windows 10. I had desinstaled and reinstaled the software 3 times but the problem still remains... can you help me.

I have an i7 intel  4g ram - 1 tera hd