They have some problems with alot of attacks and have banned some wide ip ranges. You are probably in one of them, you can email them with the problem and your ip and they will come up with a temporary fix.
lol i must be ++++ out of luck because i just plugged my laptop in and used a pay has you go dial up connection i have on it and it dont work with that so i most be in 2 ip areas that are blocked lol.
So there is no way I can even view their website w/o emailing them and requesting it?!
What kind of terrible business practice is this?
Do the the nature of the ddos attacks and the zombie machines involded they had to block some ip ranges. If you email support@vBulletin.com your ip they will give you important information so you can access the site (even if you are on a dynamic ip).