Quiz

Hi,
First, thanks very much for this promising plugin, is exactly what I'm searching for. However, I'm having problems with it:
I've got moodle 1.9 (fresh weekly version)
I've donwload the last version from the link in the plugins page, and when I click to the detailed responses, I just get the total numbers of attempts and this error (in debug mode):

Call to a member function sql_concat() on a non-object in /var/www/moodle/mod/quiz/report/responses/report.php on line 299