Keep having to log in

Hi,

I am new to RT and have rt-3.6.1 installed on gentoo. The install is
using FastCGI. I get the login screen and I can login successfully.

Whenever I select an option (new user, new ticket, etc) I am taken to the
login screen again and have to re-login all the time.

I am using Firefox to access the rt website - does this matter?

Has anyone any pointers to where I can go to get this sorted?

Many thanks
Tonino