Steps to Reproduce:
1. Log in with Joe Bloggs userCreate a new community (home-community) with 2 private pages, doclib and blog.
2. Place the document library portlet on doclib and blog portlet on blog (for aesthetics only). So now you should have two urls to these private pages that require authentication http://localhost:8080/group/home-community/doclib and http://localhost:8080/group/home-community/blog
3. Place these url's in a MS-Word document where you can click on them to launch a browser session. Start with your browser closed. Click the doclib url, you should get the login portlet with a redirection parameter to the doclib page login as Joe Bloggs and you should get successfully redirected to the doclib page.
4. With the browser still open, on the doclib page and Joe Bloggs authenticated, click on the link to the blog page. I would expect that since you have already authenticated that you should get a new tab in the browser and automatically get redirected to the blog page. Instead I am getting stopped at the log in portlet with a message that I am already signed in.