AutoCAD Inventor :: Fully Constraining Parts In Assembly?

I am trying to make a robot chassis in inventor using vex parts. I have a full library of vex parts. I have my basic chassis constrained but for some reason when i use the move command the parts still move, but then snap back into place.

Also, after giving up on the moving chassis i tried to move onto bearing flats. Bearing flats consist of 3 holes in a line that match up with the holes in the chassis rails. I constrain the face of the bearing flat to the face of the chassis rail. This constraint works and removes a degree of freedom. However, when i try to remove the other 2 degrees of freedom they dont seem to go away. I use the tangent constraint, constraining the hole of the bearing flat to the hole of the chassis rail(which is square) using an offset to make the hole centered. I constrain in both of my remaining degrees of freedom, but they bearing flat still moves.