[hnjco]

Hi

Some of my users are not able to login, when ever they open forum they get massge:

There seems to have been a problem with the
********** database.
Please try again by clicking the Refresh button in
your web browser.
An E-Mail has been dispatched to our Technical Staff,
whom you can also contact if the problem persists.
We apologise for any inconvenience.

On other side i get email everytime some one get above massege

PHP Code:

Database error in vBulletin 3.5.5:
Invalid SQL: 
SELECT user.avatarid, user.avatarrevision, avatarpath, NOT ISNULL(customavatar.userid) AS hascustom, customavatar.dateline,customavatar.width, customavatar.height
FROM vbull_user AS user
LEFT JOIN vbull_avatar AS avatar ON avatar.avatarid = user.avatarid        LEFT JOIN vbull_customavatar AS customavatar ON customavatar.userid = user.userid        
WHERE user.userid =;
MySQL Error  : You have an error in your SQL syntax near '' at line 7Error Number : 1064
Date    : Friday, September 8th 2006 @ 09:23:33 PM
Script       : [url]http://www.**********.net/******/index.php[/url]
Referrer     : 
IP Address   : **.**.*.***
Username     : *****
Classname    : vb_database 


Any idea what should be done to fix this issue?
thanx in advance!!!