I have installed 3.1.3 on two different servers. The installation on both seems to be normal. I have installed WP several times and not had problems. One install is on a Windows Server, the other on a Linux. I will call Windows server, Site1 and The Linux, Site2
On Site1, I must logon each time I make a change. It does not remember the I am logged on. The Meta does NOT change from "Login" to "Site Admin"
On Site 2, it DOES remember and the Meta changes from "Login" to "Site Admin".
I don't think this is a cookie problem, as I get the same results on FireFox 4, Chrome, IE 9. It must have something to do with the way WordPress remembers that you are still logged in. Advice would be appreciated.