I have seen what appears to be a bug. 1. Open an assy with at least one part that you can move. 2. Select it and another part and then open the measure tool. Look at the graphical distance indicators, you get the x,y,z distances on the screen as well as in the measure box. 3. Now, with the box still up, use the LMB to move the movable part. 4. Then click in the measure box to reactivate it. Notice that the graphical indicators update to the new dimensions, but the ones in the measure box do not - they are still the originals. WT