Movie Freezing on Playback on Standalone Player

I currently use dvd decrypter 4 and DVD Shrink 3.2 for ripping and shrinking movies. My writing hardware is TSSTcorp DVD+-RW TS-L632H on a dell PC. My burning software is Roxio Media Creator delivered with my dell PC and the discs are Imation DVD +R.

I burnt many discs at 4X okay with no problem on playback on my multi region standalone Toshiba SD 330 ESB DVD player. Recently all burnt discs are breaking up at the same point on each DVD.
They play okay on the PC . I then used Nero to burn the discs but encountered the same problem. The first 35 discs on a box of 50 were fine playing both on standalone and on PC. Can anyone offer any advice?

 

Please ignore this posting . I have re posted under current discussion. Sorry.