Has anybody had this problem? I have been using DVD Shrink and NERO 6 with reasonable success. However, a number of the disks backed up tend to freeze when replaying in the dvd player at varying points in the replay. Sometimes they will temporarily rectify themselves and skip scenes - however, this is the exception rather than the rule. Mostly the copy is frozen and will not proceed. The disk analysis and back-up procedures seem to be operating as intended and smoothly. Please disregard - further searching found similar problems with possible solutions.
I have similar incidents with DVD Shrink, DVD Pro, and other DVD burning programs. I wonder that is due to the quality of the blank DVD. Because as you said, some are really just working fine. Only a few might be skipping scenes and freezing when burning.