Why is server.iad.liverperson.net blocked?

[JEDI]

WinXP sp3, IE 7

i'm trying to reach live online help from my brokrage firm.

but when i click on the 'live person' icon, a popup screen for server.iad.liverperson.net comes up and i says:
Internet Explorer cannot display the webpage

What's going on? whats blocking it?

 

[JEDI]

found the problem.

it's my Host file thats blocking it.

weird that liverperson.net is on the popular blocked list that i downloaded?