sessions across subdomains problem

[chrishtml]

Hi Guys,

I am creating a membership system using subdomains. Here's how it works:

1) User logs in on members.domain.co.uk >> session is created.
2) User should be able to browse to main site www.domain.co.uk or just domain.co.uk and still be logged in.

However, the system does not seem to work properly. For some strange reason it works fine in Firefox. It also works sometimes in IE but more often than not the session will not be found on the base domain (domain.co.uk or www.domain.co.uk)

Here is the code I am using to register the session:


ini_set('session.cookie_domain', '.domain.co.uk');
    session_start();
    $_SESSION['gt_member'] = $check_login['id'];


Does anybody have any ideas why this is not working properly?

Thanks in advance.