Invalid SQL error...

[Taco John]

Hello, I've received the following error. I'm not sure what to do to correct this:

Database error in vBulletin 3.8.6:

Invalid SQL:

UPDATE session
SET lastactivity = 1381994288, location = '/BB/admincp/index.php', badlocation = 1, useragent = 'Mozilla/5.0 (Windows NT 6.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.69 Safari/537.36'
WHERE sessionhash = '2cd39a8177ad980bec9140a2272015f8';

MySQL Error : UPDATE command denied to user '504157_lopez934'@'172.17.35.117' for table 'session'
Error Number : 1142
Request Date : Thursday, October 17th 2013 @ 02:18:08 AM
Error Date : Thursday, October 17th 2013 @ 02:18:09 AM
Script : http://www.orangemane.com/BB/admincp/index.php
Referrer :
IP Address : 71.193.255.134
Username : Taco John
Classname : vB_Database
MySQL Version : 5.0.77-log