squirrelmail after installation can't login..

["Louie Miranda" <louie@axishift.ath.cx>]

I successfully installed squirrelmail on debian, as a .deb package.
I tried logging in but the webbase login always says..

      ERROR 
      You must be logged in to access this page. 


Where, my user n pass is all correct.

Which could be wrong?

-
Louie