I just upgraded to WP 3.1 and i seem to be getting 404 pages for some category pages, what is the fix for this?
STEP 1 : – In functions.php file found in your theme folder, you will see a line of code near the top near line 35 or so. It will read: $wp_rewrite->flush_rules();
DELETE this line completely and save functions.php.
STEP 2 : – As admin log into you wp-admin, head over the the settings section for Permalinks. Once you get here just click the “Save Changes” button to rebuild your .htaccess file.
STEP 3 : DONE, that was easy right?More details here: http://themeforest.net/item/instant-qa/discussion/92361?page=19#comment_content_938384