Invalid DVD navigation structure problem

ok this error has only just started, one of the dvds i had copied no worries about a month ago. so is it a software , hardware or what could be causing this error. i usually use dvd shrink 3.2 no worries, i was able to copy with RipIt4Me but i always worry with it as it deletes bits and peices that it says are not needed and does a vob clean up at the end.

DvdShrink cannot handle the encryption on newer discs. I recommend using 1click dvd copy with dvd 43