Hi there,
thank you for the information,
we are using 2015, and still have this problem with shifting viewport contents,
our vectorworks reseller help has been of no use so far, he suggested it would have something to do with that the scale of the referenced drawings where different, or that there was some sort of loop in the referenced way,
we tried ticking the 'ignore user source origin' tick in the editing reference window, and it solved some of them (by almost shifting it back to its original position, but not quite), but it didn't change other drawings back at all,
very odd, and still no solution to the problem,
do you have contact information for your vectorworks source that knew about this problem?
kind regards