Hey Rich,
The front A-frames were not the problem. On M&R's advice I did open up the face plates and tighten up all the nuts on them, which is a good idea anyways, but it wasn't the issue in our case.
The bolts I'm referring to are the ones that connect the spider arm to the carousel, in toward the center. I searched through the parts schematics in the manual multiple times but they don't appear to be called out anywhere in there.
When these bolts loosened it left the entire spider arm wobbly, thus causing the prints to be mysteriously out of register with no traceable pattern.
I can assure you that maintenance was no part of the issue here.
You have two users reporting this on certain Sportsman machines, it may be worthwhile to investigate why your bolts are spinning out. Could be the bolt quality as binkspot suggested, could be the tapping, could just be inherit to the design. I don't see any shaking on our machine but it does run everyday.