This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
You can try with the UIViewRoot object. You can store the UIViewRoot for the first page in a variable and then try setting it again in Context when the back button is called. Once set you can call the renderResponse from Context.