Yes, because they changed the bearing spec on the metal bearing.
The part number is the same, but the balls are smaller. I know on this forum it's considered bad tact to point out something wrong, but in this case they got this all wrong, they need to go back to the way it was before!
I can only advice people to make shure they get the ceramic rear if they're buying a Nova, or alternatively fit a TKO or something rear.