I made DVD+R backups of a Movie and towards the end of the movie it froze and played jerky. I read, in this forum, that it is the media, though others suggested other things. I tried an experiment to find the culprit.
1. Backed up a movie that played jerky on both my stand alone players(JVC & Panasonic) using my media(Memorex 4X). Then, I played the same disc on my friends player(Philips) and it played normally. Hum!
2. Next I made a backup, for experimental reasons only, using my friends computer and it played normally on my stand alone players. Hum!
3. Backed up a DVD movie, using his media on my system, and everthing played normally.

I used Memorex to made slide shows without incident. However, they were small compared to a movie which is resource intensive.

Conclusions:
It appears that the Philips player is more robust at handling errors than JVC & Panasonic, which are from the same cloth, basically. I checked for errors and found some, towards the end, with DVDInfo.
My media is not good, but his is.


Moral of the story-Don't buy cheap brands(unless they work for you) and hope the ones you buy come from a good lot of material.