Slow Board & "MyBB SQL Errors"

I just got the exact same error as my previous post above at 18:22pm. And again transferring from the Chat Girls thread to the Main Menu.

I got the error several times while trying to post here.

^^^^^^^^^
Same as. Really slow today.

getting this almost every time i use the forum now, is this purely just from the guest users??
if so then you really need to consider blocking guests from viewing

Funnily enough whilst browsing this very page this popped up

I blame the scrolling info bar of doom, sucks up all the memory we need

MyBB SQL Error
MyBB has experienced an internal SQL error and cannot continue.

SQL Error:
5 - Out of memory (Needed 5241216 bytes)
Query:
SELECT COUNT(post.dateline) AS postcount, post.uid, user.uid, user.username, user.usergroup, user.displaygroup FROM mybb_posts AS post JOIN mybb_users AS user ON (post.uid=user.uid) WHERE dateline > 1294775965 GROUP BY post.uid ORDER BY postcount DESC LIMIT 18


Just got this @ 19:58, leaving profile page to go to main page.

Just got this at 2001 while trying to view the bang babes section and then why I tried viewing the main menu

I got the same as above about 60 seconds ago

MyBB SQL Error
MyBB has experienced an internal SQL error and cannot continue.

SQL Error:
5 - Out of memory (Needed 5241216 bytes)
Query:
SELECT COUNT(post.dateline) AS postcount, post.uid, user.uid, user.username, user.usergroup, user.displaygroup FROM mybb_posts AS post JOIN mybb_users AS user ON (post.uid=user.uid) WHERE dateline > 1294778985 GROUP BY post.uid ORDER BY postcount DESC LIMIT 18
Please contact the MyBB Group for support.

Just got this,going from Music to the forum