Problem with a script after upgrading to mySQL 5 and PHP 5

[Cloud Strife]

I run a script and I get a mysql 1604 error on ths piece of code.

PHP Code:

       $vbulletin->db->query_write("
                UPDATE " . TABLE_PREFIX . "user
                SET thetime = '$currentunixtime'
                    WHERE username = '$theuser';   "); 


I get this error


Invalid SQL:

UPDATE user
SET thetime = '1175797034'
WHERE username = 'Rowuy')';;

MySQL Error : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')'' at line 3
Error Number : 1064

It worked prior to the upgrade but no longer works. Any ideas?