I have a multisite install with one sub site set up as a sub domain.
I don't think this is necessarily a multisite problem because things were working fine until I purchased an SSL Certificate and started mucking things up. Basically, I was trying to make all the pages on the whole site run securely. To achieve this, I ran a plugin called WordPress https. When this didn't do the trick entirely, I added some code to the functions.php file and this was the beginning of my headaches.
Fast forward (after trying for 3 days to get the site back up - messing with the .htaccess file, trying a canonical redirect plugin, etc) to now: The main page is up and the main page for the sub site is up. I can access the admin panel, but when I try to edit certain areas, I am redirected to the home page. For example, if I go to pages and click on one, it redirects me to the home page.
Help! Any thoughts or feedback on this??