Played around with Wordpress mu r1616 today (a pre 2.7 I guess) and found some weird behavior.
Made a fresh install on http://domain1.com/wp/
(Using Sub-domains)
Created a new user and tested that I could login with this user on:
http://domain1.com/wp/wp-login.php
Logged in as admin again and created a new blog. The new blog would use the domain domain2.com.domain1.com
so I changed that to just being domain2.com
and the path is still wp. I test that my new blog appears on the address - which it does:
Now I add my previously created user to the new blog and removes it from the old blog
First I try to login on the new blog with some random made up user and I'm told 'Invalid username.' then I try to login with my user with a wrong password and I'm told: 'Incorrect password.'
Last I try to login with the user and the right password and I'm just redirected to the login form with no error message like this:
http://domain2.com/wp/wp-login.php?redirect_to=http%3A%2F%2Fdomain2.com%2Fwp%2Fwp-admin%2F
Is Wordpress just not capable using 2 different domains or is this a bug?