My b2evolution Version: 2.4.5

Hi all!

After upgrading from 2.4.2 to 2.4.5 I cannot log in anymore. Or to be more precise I can login but only to the backoffice, a login to the normal blog with any user fails.

I switched on debugging and found out a litlle about what is going on but I still don't see what causes the problem.

When I call the login page I get this debug output (which makes sense):

login:
login: NULL
pass: empty
NOT logged in... (did not try)

If I try to login with a working user and wrong password I get a redirect to the login page with the error message "wrong password" and this debug output (which also makes sense):

login:
login: 'steffen'
pass: not empty
User is trying to log in.
Hashed password available.
Compared hashed passwords. Result: 0

But logging in with any correct user/pw gives me a redirect to the login page with the message "you must log in" and a debug output equal to the first (the one I get when calling the page for the first time). Each time I try this a new session is created, written to the database and the cookie is updated. After that all of a sudden the session info is not being found anymore and I get redirected to the login page.

But than again why can I log in to the backoffice?

Does anybody have any idea what might be wrong? Did I miss something when upgrading (I used the complete install option without touching the database)?

Any help is appreciated, thanks in advance!