I... i've been looking for another forums with vBulletinЎ and i've noticed that they have a lot of new things and problems that here happen sometimes... So, i've thinked '' Why don't the community don't upgrade that for another version like 4.2, 5.0... ?''
Seems great, because the new versions can make it don't lag much, and add a lot fo new options.

Even if we upgrade to a newer version, the forums will still be forums. The version of the forums has nothing to do with lag. Get a better internet connection.

The only useful feature I've noticed in the new versions is the <elseif> tag for templates. Upgrading would just be a whole lot of work without any noticeable changes.