Lets say I make a 3x3 Linear Chassi, make all sides sticky (-1 for the rotational power) put on one side of them a 3x3 of Drills, adjust 8 of the Linear Chassis to 1 and leave one on 8 by accident. Place this with the drills facing a thick wall. And then as soon as you push it with a mechanical piston it will start having trouble. The 8 drills will attempt to dig forward but the 1 drill that was left on the default setting will try to push forward with all the atached blocks. I'm unsure what happens afterwards but the entire contraption will vanish.

In case reproduction of this issue will prove problematic I will feature a quick reproduction method with pictures on request.

Here is what I think is going on:
What happened here is that the piston/bearing that was trying to move your structure was part of the structure itself. This is a know bug.

This issue has been addressed in 0.2.3. Thanks for the report and feel free to re-open if need be.