Can’t get to my dashboard after upgrade

I just upgraded my blogs and now I cant get to the dashboard!
First I could not log in, then I deleted my cookies and then I managed to login. Now when i am logged in and it tells me “you are logged in as xxx” and I click that link, instead of taking me to the dashboard, (as it usually does) it takes me to the log in page again.
What is the problem. It says that I am logged in and still it wants me to log in again and again and again…