iPhone 3GS stuck while restoring.

Hi all,
Recently bought a faulty iPhone 3GS, which had error 1601. Managed to fix this by downloading a program that updates the host file - this one:

http://www.4shared.com/file/CEz96j-s/hosts.html

This seemed to fix the problem as the iPhone (which was previously jailbroken) started restoring (I'm restoring to iOS 5.1.1), however when the restoring loading bar gets about one fifth down it just stops.

Any ideas how to fix this?
Should I try restoring to a different firmware?

And yes, it is in DFU mode when I click restore.

Any help would be awesome!

EDIT: I am now getting error 1604, for some reason. Deleted and re installed iTunes, but to no avail.
Any ideas?