I have not had this problem with the program, but I do not orient the working box to the object. I either just use the duplicate with symmetry command which sometimes, depending on the object and its orientation, puts the copy out of the scene, which I don't like to have to try and bring back into the composition and pose. Mostly, I duplicate the object, which places an identical object over the original, then click the the mirror box in the properties palette, which gives me an exact mirrored object of the original occupying the same space making it easier to move into place.