FORUM Is Down... Please Help......

[sebil]

Hiii....
My forum is down for last 2-3 days...

and it showing this error..

Database error in vBulletin 3.8.4:

Invalid SQL:
SELECT * FROM post WHERE userid > 0;

MySQL Error : Lost connection to MySQL server during query
Error Number : 2013
Request Date : Thursday, September 17th 2009 @ 02:43:02 PM
Error Date : Thursday, September 17th 2009 @ 02:43:06 PM
Script : http://www.malludreams.com/
Referrer :
IP Address :
Username : MalluDreams
Classname : vB_Database
MySQL Version :

and i spoke with server people about this...

they said:-

Support Department: the problem is at your forum
sebil: but the problem is still remain
Support Department: the error log shows "out of memory"
sebil: what does it mean
sebil: ?
Support Department: we did increased it to 512MB but it was not enough
sebil: what i have to do now
sebil: ?
sebil: do u know... anything wchich can help me
Support Department: read vbulletin forums
Support Department: something is wrong with your forum itself
sebil: ohhh
sebil: i will get support from there then..
sebil: thank you very much indeeed..
Support Department: Is there anything else I can help you with ?
sebil: nop thanks
Support Department: have a good day then

please.. any one could tell me.. what i have to do