ASP MVC - Bunch of random characters in POST request route string

[AndrewA]

I am trying to log in to my own application, and i have discovered something strange. When I am sending a POST request to a login controller, it somehow redirects itself to a GET login controller, and displays login form with an action set to \[code\]http://localhost:5898/(X(1)S(1tgv3m2psb2cxqaw4koiyhyt))/Account/Login\[/code\]. Now what the hell is this \[code\](X(1)S(1tgv3m2psb2cxqaw4koiyhyt))\[/code\] thing? Why is it there, and what does it do? And on top of that, how do i get rid of it? I do not want it in there...