You can repeat this test and also run it from different locations, different connection types and browsers, and so on.
You have one 404 error in your waterfall, apparently a missing image.
As you can see by the waterfall chart, once the "handshake" between the server and the browser is finished, your vBulletin then loads in less than one second with only 584kb of data loaded and only 47 requests.
The issue the host is reporting has nothing to do with your vBulletin installation, it has to do with them overselling this machine it is on.
Get a responsible host.
Holy moley... thats a pretty slick tool. I fixed the missing image - it was an upper case/lower case issue.
--------------- Added [DATE]1387501257[/DATE] at [TIME]1387501257[/TIME] ---------------
Speaking of search engine bots... I thought for sure that I had something that constantly showed my the names of the search engine bots that were hitting my site - If I remember correctly, it was real-time.
Was I dreaming??
Any good recommendations for a new host (like one as fast as vBulletin.org)?