1) set some low velocity;
2) switch to a turret;
3) switch to Pan view, zoom out and turn the camera as needed to see the turret, ship and some area behind it;
4) engage SPEC manually
5) the turret stays while its ship moves, then sticks at the new place - in ship or emptiness - and moves with the ship again!
selling the turret doesn't reset its location, but loading the game saved in this state does.
obviously, this situation should happen only by a rare mistake, but maybe this can help to pin down at least some of existing subunit bugs.
Anonymous
how it looks: http://i945.photobucket.com/albums/ad292/TBeholder/screenshots/bugs/Screenshot260.png