I installed and activated this plugin a few days ago. It gave this single error in the error log when I activated it:
WordPress database error Table 'user_wrdp1.wp_0_comments' doesn't exist for query SHOW COLUMNS FROM wp_0_comments LIKE "openid" made by activate_plugin, do_action('activate_openid/openid.php'), call_user_func_array, openid_activate_plugin, openid_migrate_old_data
The problem is
wp_0_comments should just be
I am using PHP 5.4, WordPress 3.5, OpenID 3.3.4.
Other than that it seems to work OK.