Multisite Common Login / Users

Hi all,

I have a multisite network with 3 sites. The sites are subdirectories using domain mapping.

http://www.onesys.ie (main site, no mapping)
http://www.pegasusopera.com (mapped domain from onesys.ie/onesysnews/)
http://www.pegasusopera.net (mapped domain from onesys.ie/onesysforum/)

These sites all share the same styling, and are intended to be perceived by the user as ONE cohesive website… however I’ve been having a nightmare with the login / registration system!

What I want is that when a user logs into any of the 3 sites, he/she should be logged into all 3 sites. When the user logs out, then he/she should be logged out of all 3 sites! This is not the case at the moment.

I want the user to be taken to whatever page they were viewing after logging in / logging out. I can achieve this on the main site, but on the mapped sites the user is taken to wp-login.php.

Surely there’s some way of making the login system behave the same way across all sites on a multisite network?!

Has anyone tried to achieve this before? Any help would be greatly appreciated!!