There are a number of places where Samigo is returning markup as a result of a POST operation instead of processing the POST with no markup and doing a redirect. Luckily JSF generally solves this with a configuration change - you simply add <redirect/> to the <navigation-case> entries and JSF handles everything.
The easiest way to reproduce this is to open Samigo in a frame by itself and then switch among the top four options. You can watch the dev console. You will see POSTs and the URL will reflect the page you are coming from in the navigation - not the page that you are seeing. Also when you use the back button you get the "repost form data" dialog.
As we move to frameless approaches the details of tool url will start to be more obvious in the location bar, and users will start to use the back button as well as bookmark deep links into the application right from the location bar. So we need to have these URLs looking nicer.
I have done some initial testing adding the <redirect/> rule to the four navigation rules for the top navigation menu and things work great.
My instinct would be to just add <redirect/> to every URL that was not being used as AJAX or as some kind of web service. Since the logic only triggers on POST, I can't imagine any harm - but of course it would be good to test the code after making the change.