SSO for facebook android gives me invalid_key every time, i tried to debug by every means but it is not working. So is there any way/hack to disable Single Sign on and work
You likely don't want to use FORCE_DIALOG_AUTH as the solution because this disables the very useful Single Sign On feature completely. Instead, if you go through the steps of setting up your application properly with Facebook, that should address the invalid_key issues. You can find a detailed explanation of this on my blog:
http://sean.lyn.ch/2011/07/android-the-facebook-sdk-sso-and-you/