Keeping getting this notification...

[Eruantien]

...and I don't know what it is or how to fix it. This is sent via e-mail relating to my forums. Mods, if there is something that should not included- please edit it out.

Database error in vBulletin 3.8.4:

Invalid SQL:

                               SELECT user.*, (user.options & 512) AS invisible , avatar.avatarpath, NOT ISNULL(customavatar.userid) AS hascustom, customavatar.dateline AS avatardateline, customavatar.filedata_thumb, customavatar.height AS avheight, customavatar.width AS avwidth, customavatar.width_thumb AS avwidth_thumb, customavatar.height_thumb AS avheight_thumb

                               FROM userlist AS userlist
                               INNER JOIN user AS user ON (user.userid = userlist.relationid)
                               LEFT JOIN avatar AS avatar ON (avatar.avatarid = user.avatarid)
                               LEFT JOIN customavatar AS customavatar ON (customavatar.userid = user.userid)

                               WHERE userlist.userid = 84
                                       AND userlist.type = 'buddy'
                                       AND userlist.friend = 'yes'

                               ORDER BY RAND()
                               LIMIT 0, 1;

MySQL Error   : Got error 28 from storage engine
Error Number  : 1030
Request Date  : Thursday, September 17th 2009 @ 05:24:48 AM
Error Date    : Thursday, September 17th 2009 @ 05:24:48 AM
Script        : http://www.loremaster.org/member.php?action=getinfo&u=84
Referrer      :
IP Address    : XXX.XXX.XXX.XXX
Username      : Unregistered
Classname     : vB_Database
MySQL Version :