From:  Michael Gibson
3858.3 In reply to 3858.1 
Hi Andy, so it sounds like you've got it figured out, but just in case - that "History" command allows you to enable or disable history updates on an object.

So for example after you do a Mirror, the mirrored result object remembers that it was created from doing a mirror of the original object, and if you move the original object around the mirrored object will update as if the Mirror command was run again on it.

If you didn't want that to happen you could select the mirrored object, and then run Edit > History, and then click the "Disable update" button. Then history updates for that mirrored object will be turned off, and it will no longer update itself automatically when the original object is moved.

Right now in MoI history only works in some kinds of circumstances where all the objects involved in the history chain are present in the model. The history chain will get broken by some kinds of edit operations like booleans, because after the boolean is done the original unbooleaned objects are not in the model anymore for the history update mechanism to access. There's some more description of this here:

In the future I do want to make the history function deeper though so that it will automatically store the original objects in cases like that and be able to access them to avoid breaking the history chain.

- Michael