This is interesting. I'm sort of with Loren on this one. Have you had your tires balanced?
The worst that happened with my side dinette cushions in my '02 Scamp was that the backs would fall
down on the seats. The previous owner complained that whoever sewed the cushions must have been blind because they did the patterns for the backs up-side down when the cushion was upright (zipper down)! I
had the trailer for six months before I realized that there are seat cushions and back cushions and they are different lengths.
AFTER I figured out that the back cushions go in first and sit on the seat, and THEN the seat bottom cushions go in, slide back against them, and secure them in their place, they haven't moved at all. AND
the patterns match correctly!
I can post photos of mine with the cushions both ways for comparison this weekend. And of course, it's always possible that Scamp made some revisions in the side dinette structure between the '99 and '02 model years...