I've used the "Duplicate Current Page" function and now find that when I make some formatting changes on the duplicate (e.g. changes to positioning and sizing of elements or columns) these changes are affecting the formatting on the original - is there a way to break the connection?
Thanks in anticipation.

Either give the column on the new page a different class name or an ID name and then make sure you select the appropriate one to apply your changes to when you make them.

Thanks Eric - that worked - and another valuable lesson learned for a robust yet elegant website - be systematic and orderly!