This is one of the weirder problems I've ever encountered - hoping someone else may have come across it (and hopefully a fix too). I have a cargo container, and a freighter it's supposed to dock with. The only problem is, once it's docked with the freighter, it starts spinning wildly. so fast, in fact, that getting too close will instantly kill you. It also spins in FRED whenever the two models are docked together and you move the model.
I've confirmed it's the cargo container and not the freighter by docing them both to various other things and seeing what happens, but beyond that I'm utterly stumped. The container has what looks to me like a normal dockpoint, it has normals for every point and a spline path, it's arranged so that point 01 is 1 unit ahead of point 00 along the appropriate axis (aligned with the freighter's dockpoint), I've fiddled with the mass of the pof (Same symptoms at both 180 and 180000) - I'm out of ideas, and my usual go to guy (VA) seems stumped too. So, err, has anyone else had this problem, or have a suggestion?