@JohnHoward,
Please carefully read my reply #11, re trying without using DHCP, and understand the configuration of your router(s) between Arduino and server.
Also my reply #13, your initial problem of connection issues had little to with what the OP, royalldonkey was asking and so we are mixing up this thread with multiple issues.
@royalldonkey, can you tell us your status?
Apparently I need to explicitly say I was trying to solve the OP's problem for him, hence "my POST above should do what you are trying to do." And I thought I had, with one reservation which I had noted. It's not terribly polite to lash out at someone about 'thread hijacking' for simply trying to help. Or at any time, really.