Copied DVD will play on one dvd player but not another

I have been backing up some of my dvd's. Unfortunately, some times the back up DVD will play on some dvd players but not on others. Any ideas about what the problem may be.

 

it will be the disks.

 

I have used a couple of different types-SONY and Verbatim and it happens which ever I use?

 

+R and/or -R?

 

I only use +R. I get better copies

 

What does "better copies" mean? A "copy" doesn't care what disc format it resides on, nor does it influence the quality in any way. But it most certainly makes a difference to many standalones.

 

When I use R- discs I get lots of problems during recording which means they get thrown away. I rarely have that problem with R+ discs.