I can't seem to access category archives, whenever a user tries to access the category archive the page is directed to the homepage. Monthly and author archives work fine though.
I've replaced my .htaccess with a stock version, even edited my current one to see if something had changed.
Not seeing any errors in apache. I went from 2.9.? to 3.1 last night.
archive.php (don't think it's this file, i couldn't find deprecated code.)