help on device buffer jump

Hello everyone i am sry if this has been answered already I did some searching and could not find anything. I have been backing up movies for sometime now but all of a sudden the device buffer is jumping all over. I dunno what could have happend its been working fine for quite some time i use shrink and decrypter i got all the updates for them as well.
Will the device buffer jump effect my back-ups like will it make coasters? Any info would be appricated.