Yeah I experienced this as well. First, I thought, well, traction (friction with the ground) is really low, keeping sliding as if on ice. I had a large storage unit, a 1-seat and a large solar panel. Then I put a dark-green research item on it, and it started to bounce around like crazy, until I finally managed to take it off. It actually stopped bouncing when I took of the solar panel.
Probably some weird bug with the Havok engine (if they use that).