even if i change the assignment from cntrl-z to something else like show planes, it still retains the undo function deepnding on the command i am using. for example when using mates i like to toggle show planes and i had reassigned cntrl-z to do just that since it is conveniently located on the keypad. undo is set to U. the show planes works fine until i finihs a mate command. once i exit the mate command i hit contrl-z to toggle the planes off but it undoes the last mate. wonder is this is a command buried int the windows OS?