Webpack login

I searched around for an answer and a few threads actually brought up the question but none really got answered. So I figured I'd ask directly.
All of the webpacks I downloaded have exactly one problem: The login doesn't work. Account creation works and I'm able to login to my server with an account I created through the website, but when I try to access my account so I can post news, it doesn't do anything. I enter the info, but it sends me right back to where I login with no error or anything, making me enter it again.

Is there a fix for this? Thanks in advanced.