You do not have sufficient permissions to access this page
Are you getting "You do not have sufficient permissions to access this page." errors everywhere in the WordPress admin? I had this happening on a site, apparently the problem is that somebody changed the database prefix. It's a little suprising that this would totally break the admin, but whatever...
As usual, make a DB backup before running this code, yadda yadda..
UPDATE PREFIX_usermeta SET meta_key=REPLACE(meta_key , 'OLD_PREFIX_', 'PREFIX_'); UPDATE PREFIX_options SET option_name='PREFIX_user_roles' WHERE option_name='wp_user_roles';