If your WP permalink structure is /index.php/%postname%/ , your permalinks will break in WP 2.6! Temp fix: manually set category tag bases.
- If you’re using Linux/Apache on your webserver, you don’t really need the index.php anyway. Try removing it. The index.php thing was only meant for IIS servers, which don’t support mod_rewrite.
- If you need/want the index.php to be there, then on the Settings->Permalinks screen, add some values in for the category and tag bases. The words “category” and “tag” will do just fine. As long as they are not blank, this should work around the bug.
Regarding the first solution, do note that losing the “index.php” will not cause any existing links to your single post to break. For example, http://wplover.com/index.php/our-rights-wordpress-theme/ and http://wplover.com/our-rights-wordpress-theme/ points to the same page. So no worries here.