If you have WordPress 3.0.5 install and upgrade to 3.1 make sure you have removed WP-Hive !! Don’t do it without a backup either !!
otherwise if you get an error relating to “fatal error: Call to a member function suppress_errors() on a non-object in ………../ wp-content/plugins/wp-hive/includes/class.wphive.php on line 69” and you are going to have to downgrade to 3.0.5 – deactivate and then remove it before reupgrading again.
Don’t do this without a backup of the entire wordpress folder!!!!!!!
In my case I backed up the entire wordpress folder and then downloaded the 3.0.5 from here http://wordpress.org/download/release-archive/ on the wordpress host and copied in the files in the root folder and the the wp-admin and wp-includes but NOT the wp-content.
Reaccess the site and deactive / remove the wphive if you are not actually using it. If you are it would be worth going to http://wp-hive.com/ to find out if any options are available to migrate – or you will have to stick with 3.0.5