2 projects share same login?

Ok, here is what I finally did.

1. I decided the best course was to leave each application separate, using their own databases. This limited any possible interaction between the two (which, when I tried it as one database and a single session, there was.)
2. Make sure each application has a separate SESSION_COOKIE_NAME.
3. For single signon (SSO), I used django-sso. This works quite nicely, seems fairly secure, is simple, and depends on a secret key you store in each project's settings file.
4. I wanted to make everything seamless, so that when a user logs into the django-cms project, osqa acts just like some additional pages (via a url staring with /osqa). In order to have everything consistent, including registration, when a new user is created in the cms, I needed to have one created in OSQA. So I added django-piston to OSQA, in order to create some REST api calls.
5. Via REST, when a new user is added in the cms, a call is made to OSQA, and a user is added there (including an entry into the forum_subscriptionsettings table, which apparently is necessary for osqa to run correctly). I am not happy having to do this, but could not see anything simpler to keep the OSQA app happy.
6. For development, I use the django "runserver" command, and have each project running on a separate port on my local machine (running linux).
7. To deploy, I used mod_wsgi. In the Apache virtual host file, I have two entries for WSGIScriptAlias - one for the cms project, at "/", and one for the OSQA at "/xosqa".
8. It turns out that which the WSGIScriptAlias set up in this way, leave FORUM_SCRIPT_ALIAS to "". Everything works just fine (not sure why, though!), so that when you go to /xosqa, the OSQA project works correctly (yes, of course you have to add this "osqa" to your url's in the cms project, which calls djangjo-sso, which then calls /xosqa with arguments for logging into OSQA via django-sso middleware).
9. For grins, since I had the REST framework, I added a function to get the last 10 questions, for displaying in the cms.
10. I made some mods to my custom OSQA skin to remove info for registering or even logging in. I added a menu at the top which duplicates that on my cms pages, with a "Welcome <user>", a "Home" (which goes to the cms home), and a "Logout" (which calls the cms logout).