Hi , had the same problem with my -R discs, verified after burn and all said 100% , on the computer using WINDVD no problem then playing on my pioneer dvd player pixelations and hangs at the end of the movies.

What I found out is that burning 2x on my Sony 500 was not fullproof, probably it used the lossless linking sometimes which PC drives have no problem with but standalone dvd player may have serious problems with.

Solution:
I forced the burner to burn 1x max on -R's and since then I had no problems.

It's weird cause a friend of mine has the same Sony and the same brand DVD-R's but can burn 2x without problem, I guess it also is dependend on motherboard, OS etc. etc.

Greetz Kjelt