DVD BRAND

I have used Memorex DVD’s for my movies and never had a problem.
3 out of the last 5 movies I made would hang up and stop.They were made from one stack of DVD’s that I bought. Backing up and fast fowarding would get past the “bad spot” so to speak. This is what I am asking or don’t understand. With the high RPM’s that these discs turn how could a manufacture brand of a DVD cause a disc to hang up?