Changed my mind, because it basically dissolves into "check your settings, open your ports" over and over again. Literally.
If Hamachi worked, I'd safely gamble it's one of two things. Didn't forward ports through your firewall, or you used your internal (192.168.x.x) IP address for the zone_settings.zoneip field. The zoneip should be the address you receive from whatismyip.com. Hell, if Hamachi worked, that guarantees it's running on the internal address instead of external.
If you can connect from your own server, but no one else can, see the explanation for Hamachi.
Side note:
DMZs are great for testing, but not a permanent solution. Think of it like putting your television outside to test your reception, and then leaving it there permanently when the reception is better. Don't be surprised if it gets broken or goes missing.
Instead, forward your ports. 