Receiving this error.. loading times severly slow

[mojoman]

Warning: mysql_query() [function.mysql-query]: Unable to save result set in [path]/includes/class_core.php on line 408

I did some googling, but couldn't find any definite answers on this error.
The board is running incredibly slow for everybody and this message sporadically appears usually when clicking the index.

Does anybody have a solution/fix to this problem?

Thanks in advance.

[kh99]

This error is mentioned a bunch of times on vbulletin.com. Here's one thread that actually has a suggestion on how to solve the problem. :) https://www.vbulletin.com/forum/showthread.php/361956-Site-keeps-crashing?highlight=Warning:%20mysql_query()%20Data base%20error

[mojoman]

Well, I tried repairing all tables twice now and it's still happening. Would there be any other reasons?