Forum my vBulletin site has gotten sooooooooooooooooo slow
 

I am relatively new to owning vBulletin (4.x), and lately when I (or anybody else) accesses the forums (also the Administrator area) the performance has slowed considerably. Today, it takes so long to access anything that my browser is timing out. I can't even view a post.

The site is consistently slow on several computers. This is not happening on other web pages, or even other vBulletin forums in which I participate. Can someone help me troubleshoot this or tell me where to look to fix it?

Thanks.