Can't access a specific website from my network usign Fortigate 100D

Hi,

I'm new here, so I don't know if this has been questioned before, but here it goes:

There's a specific website that I can't open from my network, but in this case, I don't get any error or message as response, like it was any rule causing it. It just says the webpage can't be displayed (on Internet Explorer), like in this pic:

https://projects.cs.uaf.edu/redmine/attachments/420

The website is [link]http://portal.protectorbrasil.com.br[/link]

We use here a FortiGate 100D with the v5.2.2,build642 (GA) firmware version.

That's all, just tell me if any further information is needed, any help would be very appreciated.