I've been duplicating some base maps for individual encounters for the old dragonlance modules.  Because these maps are standard and basic, there is text on the map layer I have built explaining what some of the large rooms are.  When I duplicate the standard map to create a set piece one for a specific encounter, the text on the map layer is not being duplicated.  I can move the text on the map layer to the GM layer, and it transfers fine, so it's specific to that text/map layer combination. On a related note, duplication of a map has had some issues in how items are being layered when the duplication occurs.  I've had a number of issues where items in the map layer were laid down in a different order, thereby creating map problems.  Also, when adjusting to the above problem by moving text to the GM layer, when moving it back to the map layer on the duplicated map it isn't 'on top' either, so it first has to be moved to the front and then moved back to the map layer.  Otherwise, it's buried under floors or either items.