Log in, log in, log in

Is it just me being a bit thick.....  Once I have logged in to the club website, why do I keep seeing the log in page each time I try to do something - review a site or comment on a post for example?  Then I have to go into site search etc. etc and click on 'review this site', low and behold the log in page comes up again.  It's bizarre!  In the top right hand corner, I can see that I must still be logged in anyway.  Sometimes I just give up.