Congo Jr Second display problem

Dear all,

I have a Congo Jr. (First generation with dual DVI D adaptor). After I updated to 4.1.2 the second monitor stopped working. I read the release notes and it refers to this problem but the proposed solution of restarting the console doesn't solve the problem. I want to downgrade the software but during the procedure of installing an older version a pop up window says that I have to uninstall the already installed version. How exactly can I do that?? Has anyone the same problem?? Any solutions are more than welcome!