Problem description: 
If you create a new master slide you have 5 text areas that you can edit, but you cannot add an additional one. I'd like to create a master with two text areas side by side in the main content area for example. Another case is when you delete the existing placeholder, you cannot recreate it with the insert menu. 

Steps to reproduce:
1. Create a new odp presentation
2. Go to View => Master => slide master
3. Try to create a new text placeholder in an existing master slide

Current behavior:
not possible. You cannot even copy an existing text placeholder

Expected behavior:
There should be a context sensitive entry in the Insert menu that lets you create as many text placeholders as you like. Additionally, you should be able to copy a text placeholder just like every other object.
              
Operating System: Windows 7
Version: 4.0.0.3 release