WordPress MU

I have setup domain mapping and it works perfectly.

The only thing I would like to change is to set the session for the user to work on any of my wordpressmu blogs.

Kinda like Wordpress.com and .org. Different domain, but cookies recognize one user

Basically the way it works right now, is that a person can login to the main blog, and that will automatically log them into anything.wordpessmusite.com

However if I use domain mapping, and create a website named xyz.com the user is not automatically logged into the site. They can however still use their same username and password.

Are there any experts online here that may know how the actual wordpress website is doing it so that a person does not have to login to each site separately?

Is there a fix for this problem yet?

So far all I see are people complaining about the same thing.

wordpress.com doesn't seem to have this problem...

what plugin are they using, if there is no fix for the domain mapping plugin?

Donncha is working on something to get this to work. From what I understand, he was prevented from incorporating what wordpress.com uses into his plugin. There is a version of the plugin from user johnnytee that removes the login/logout problem by doing things just a little differently. It's in thread:

http://mu.wordpress.org/forums/topic.php?id=10882