[Max Taxable]

Use CloudFlare CDN, it will speed you up greatly. And, it's free.

Horrible, horrible test result from Google's Patrick Meehan:

http://www.webpagetest.org/result/120105_F6_2RG6F/

It also caused a warning on that browser, "A script on this page is causing Internet Explorer to run slowly..."

Try disabling the plugin/hook system and try that Meehan test again. Also, set the default vBulletin style as the default style, and see what happens. I don't think you have a server or hosting issue, since your first byte time is decent.

There's third party content from "getfirebug" that looks suspect.

In fact, when you view the details of the test you can see the "getfirebug" stuff is causing alot of load on the CPU of visiting computers:

http://www.webpagetest.org/result/12...G6F/1/details/

They appear to all be images, but the third party server they are hosted on doesn't seem to be responding very well, slowing you down massively. Try obtaining these images if they are important, and hosting them up on your own server, eschew third party sources. You can't rely on them.