Database error, plz help me

[mrwinxp]

My website is working but when I login to admincp and click on Scheduled Task Manager, it say:

Database error in vBulletin 3.7.4:
Invalid SQL:

		SELECT cron.*, IF(product.productid IS NULL OR product.active = 1, cron.active, 0) AS effective_active
		FROM cron AS cron
		LEFT JOIN product AS product ON (cron.product = product.productid)
		ORDER BY effective_active DESC, nextrun;

MySQL Error   : Unknown column 'cron.active' in 'field list'

Error Number  : 1054

Request Date  : Monday, November 17th 2008 @ 11:45:37 PM

Error Date    : Monday, November 17th 2008 @ 11:45:37 PM

Script        : http://forum.xxxx.com/admincp/cronadmin.php?do=modify

Referrer      : http://forum.xxx.com/admincp/index.php?do=nav

IP Address    : 117.xxx.xxx.xxx

Please show me the way to fix it. Thank you very much