Ever since the single sign on I have had trouble staying logged in. I have not worried about it much because I was not trying to post.
 
Then when I did try to post it said that I did not have sufficient privileges. I just cleared the cookies from the old forum site and cleared the cache and this is a test post. Has anyone else had trouble posting since the rollout?
 

Clearing cookies is the solution. Many browsers allow you to do this selectively. I had the same problem.