on my site, I had converted categories to tags. But in order to save my search engine rankings, I used word "category" as Tag Base in Permalinks Settings page. So all my tag pages were served like http://example.com/category/mytag
I recently upgraded my site to 3.1 from 3.0 after upgrade this permalink structure wont work. If a tag is also a category then it would display posts otherwise "Sorry, no posts matched your criteria."
I have checked .htaccess file and updated permalink settings to refresh it but nothing seems to work.
So what is changed since last version?
How I can display tag posts with /category as tag base?