Hi Guys,
Got an issue with all devices on my BES at the mo.

Whenever I try to browse websites, I have to reload/retry to goto them 2 or 3 times before I can actually get to them.

The error message I get on the BB is as follows

HTTP Error 400: Bad Request

The server could not understand the page request, or was unable to process it for some reason. Please try loading a different page.

Details:
Unknown host
www.website.com:80

Any ideas?

Basically the URL address is not understood by BES' MDS-CS. Try this.

View Document

This looks more like a problem of the DNS resolver running on the BES server.
try this:
go to the console of the BES server or connect via rdp,
open a dos command window.
type:
nslookup
www.nameofsiteinquestion.com

what happens ?