WordPress generates deprecation notices if I set WB_DEBUG to true.
The deprecated function calls are:
On newer WP versions there are maybe more warnings.
In addition, I get the following PHP notice:
Notice: Undefined index: statpress_action in /var/www/wordpress/wp-content/plugins/statpress/statpress.php on line 149
If you do not have much time, I can maybe write a patch some day.