Do you have the default prefix for q2a tables?
This is set in the cronjob file that you manually call.
you could also run a mysql query directly on first of the month:
INSERT INTO `qa_userscores` (userid, points, date) SELECT userid, points,
DATE(NOW()) AS date from `qa_userpoints` ORDER BY userid ASC;
As many people are not familiar with mysql and php I will think about changing the plugin so that it automatically updates the database table as soon as the admin visits the admin/plugins page. This should be easier for all users.