Links going to www.url, Discuss doesn't recognize login

I'm hoping you guys can help steer me in the right direction here, as this issue seems to be affecting EasyDiscuss the most. When a link is generated by a plugin, such as the DIscussion for JomSocial, the link URL contains www. When this link is followed, the user's login is no longer recognized, and they are prompted to log in again.

How do I stop this? It's driving me nuts. I would think there is a way for either to be recognized, with or without the www....