getting hack?

[dtv100]

i getting some weird error and all from same user every other hour .

Invalid SQL:

SELECT forumid, moderatorid, permissions, permissions2
FROM moderator
WHERE userid = 11926 AND forumid != -1;

MySQL Error : MySQL server has gone away
Error Number : 2006
Request Date : Saturday, May 16th 2009 @ 04:22:12 AM
Error Date : Saturday, May 16th 2009 @ 07:16:50 PM
Script : http://www.domain.com/
Referrer : http://www.domain.com/forums/login.php?do=login
IP Address : 74.180
Username : mesl|ce
Classname : vB_Database
MySQL Version :

Invalid SQL:

UPDATE session
SET lastactivity = 1242470132, location = '/', loggedin = 2, inforum = 0, inthread = 0, incalendar = 0, badlocation = 0, useragent = 'Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.0.10) Gecko/2009042316 Firefox/3.0.10 (.NET CLR 3.5.30729)'
WHERE sessionhash = '3ae982bda0fcb2c1fbd4a3ee2533e039';

MySQL Error : MySQL server has gone away
Error Number : 2006
Request Date : Saturday, May 16th 2009 @ 06:35:32 AM
Error Date : Saturday, May 16th 2009 @ 09:13:09 PM
Script : http://www.domain.com/
Referrer : http://www.domain.com/forums/login.php?do=login
IP Address : 74.180.
Username : mesl|ce
Classname : vB_Database
MySQL Version :