Is your MySQL Database using INNODB or MyISAM?

Its an option.

 

...that sounds atrociously primitive for commercial software vBulletin. Has no one suggested a hash based inverted index table yet? Faster, more powerful, saner, lets you make the thread table an InnoDB table as is proper.

 

Wayne, I never understood the difference between fulltext searching and vBulletin's own search method (not sure what it's called). Is one better than the other in terms of results and relevancy?

 

I wrote of the basic differences a while back here: MySQL Fulltext vs. vB Search Types - vBulletin Community Forum

Basically the built-in search is the same search engine that you'll find in vBulletin 1 and 2. It is not very advanced or sophistated. Most of the work is done via PHP.