Problems playing 50GB backups on Sony BDP-301: How to burn BD-RE 50GB DL?

I am new to this forum. I have made a few backups of commercial blu-ray movies and saved them to my hard drive.

I used AnyDVD HD and created an ISO with Alcohol 120%.

Everything seemed to work fine when creating the ISO files.

When i burn my ISO files onto a Sony BD-RE 25GB with Alcohol 120% the movies playback perfectly.

When i try to burn my ISO files onto a Sony BD-RE 50GB DL, the movie loads and shows the loading bar from the blu-ray with pictures of whatever movie i burned, and then the timer on the player display goes to 00:00:00 and nothing moves.

Is there a certain way to burn these movies? I am using a Sony BDP-301 standalone player.