Can't log in to admin account with the right password

When i try to log into the admin account nothing happens at all. My user-account works but when i try the admin account it just sends me back to the login page without giving me an error. If i type in the wrong password when trying to access the admin account it does give me a password-error.

It worked just fine earlier but now its broke..

log:
[Fri Apr 15 14:07:22 2011] [error] [client %%my-ip%%] PHP Notice: Undefined index: login in /usr/local/ispconfig/interface/lib/classes/plugin.inc.php on line 140, referer: http://%%my-domain%%:8080/index.php

OS: latest ubuntu server

I'd really appreciate help, thanks!

edit: i have tried it with different browsers, and different computers on different networks, still no luck.
edit2: i tried making my user account an admin account by changing the typ value in the database. Now that account does not work either, when i retested it to user again it started working

 

Nope, not lately.

 

Ok, i figured it out, it was one of my modules acting up. Sorry to bother and thanks for the help

 

Please Explain

Please explain what you did. I got the same problem but couldn't find a way to solve it.