New Blog Signup Bug after Multi-DB installation

Hello, I have just finished installing Multi-DB, Vaughuan was of very good help to me, thanks to him. However, I just noticed that when a new user signs up and create a blog, the user does not see a SUCCESSFUL page but is redirected back to my homepage (12blog.org). And the blog that is created takes the default wordpress twentyeleven wordpress theme. The Default theme I set at the back end no longer works and also Using unlimited branding, TEXT change for "Proudly powered by Wordpress does not change too. This was not so before I used multi-db. Can someone help me out?

Thanks.