Forum loading very slowly... what's causing it?

[wman]

The site http://www.sierraleone.com is very slow and often just keeps loading for minutes.

Is it the style (Kirsch), vbSEO, or some error we made when upgrading?

With the default style, it's a bit faster but still keeps loading forever on some pages.

Also, sometimes a user is logged out after having logged in... and then logged in again automatically when he clicks on some topic. Very confusing.

Any thoughts/ideas?

Thanks!