When switching to/from documentation map new documentation maps are created.

Steps to reproduce:

1) Maps menu contains no maps.
2) Call Modes/File menu item
3) Maps menu contains 1 map - "File: root".
4) Call Help/Documentation menu item
5) Maps menu contains 2 maps - "File: root" and the help map
6) Press Ctrl+Right, you get the file view
7) Maps menu contains 2 maps - "File: root" and the help map
8) Press Ctrl+Right, you get the documentation view

What should happen:

Maps menu contains 2 maps - "File: root" and the help map

What really happens:
Maps menu contains 3 maps - "File: root" and the 2 help maps.