I upgraded to WP 3.1.3 yesterday, and I don't know whether this issue is related or is a coincidence, but suddenly, whenever a user outside of the main blog (which is set as the tags blog) updates a post, it is creating a duplicate of the post in the main blog instead of simply updating the original post.
I've been using the WP multi-site setup along with sitewide tags successfully for nearly a year and this is the first time I've encountered this problem.
Here is the main blog: http://mangabookshelf.com/
You won't see duplicate posts there, because I've been deleting them as they occur to keep the front page clean, but it is happening with posts from each of the site's subdomains. Again, I have no proof that this is due to the 3.1.3 upgrade, but the timing does coincide with that update. I realize that I could probably downgrade WordPress to test this, but I wanted to ask about it first, since that's a more laborious process than the automatic upgrade was.
Is anyone else experiencing this issue along with 3.1.3, or has anyone experienced it in the past?
Any help greatly appreciated!