I just install a fresh copy of WP 3.3 and Installed WATS 1.0.55. I am receiving
Warning: call_user_func_array() expects parameter 1 to be a valid callback, function 'wats_user_register' not found or invalid function name in /x/x/x/wp-includes/plugin.php on line 405
Warning: Cannot modify header information - headers already sent by (output started at /x/x/x/wp-includes/plugin.php:405) in /x/x/x/wp-includes/pluggable.php on line 866