This is similar to the problem I reported in my more recent post. After upgrading to Genesis 2.0.1 and GSS 2.0.1, here is what happens:
1. previously placed simple sidebars still work if the page was created before the upgrades and had a simple sidebar attached to it.
2. New pages created won’t be able to get the simple sidebar (the sidebar area will be present but completely blank
3. When you edit any page (whether created before or after the upgrades), the panel for Sidebar Selection is non-functional. You see the title of the panel (“Sidebar Selection”), but there is no dropdown at all even though in the plugin you have created several sidebars. Intead, there is an extra border below the title box as if it is trying to form the panel but can’t
I reverted to Genesis 2.0.0 and Simple Sidebars 2.0.0 and got partial resolution. See my newer post dated 9-9-2013 for details.