I had the "host" in the servers file without the http, yeah.
From what I can see they have a number of hosts you can try depending on server load and your location:
nl2.btcguild.com Netherlands
nl.btcguild.com Netherlands
uscentral.btcguild.com Texas
uswest.btcguild.com California
useast.btcguild.com Florida
de.btcguild.com Germany
So if you have tried all of these and still cant connect try entering a servers IP (rather than its DNS hostname) eg:
For uswest.btcguild.com server enter 69.42.217.226 instead