I use Memorex DVD+RW 4X. I burn at 4X speed. Had great success with
this media until about the beginning of November. The Sony burners still burn files and all, erase ok, and seem unaffected overall. This litte intermittent problem has developed resently. Maybe it is not Sony. It may be some other
movie label. If not sony then who.

How do you explain the ok outcome on a seperate identical system. All hardware software the same. Both affected when using Sony burners. Both have the same results. Remove the Sonys and put in the Memorex and everything is back to normal.

I use two systems for this exact reason, to troubleshoot and compare.