Firewall/NAT

Ok, I recently set up my monowall and its works great! I configured NAT for RDP by opening up port 3389 and that works fine from within the LAN and outside from the WAN. I can rdp into my machine from the outside if im using windows remote desktop. Well, I have an app for the iphone called Mocha RDP lite and it cannot remote into my machine from the outside like it used to when I had just a linksys router and port 3389 forwarded. Any one know why this could be. The iphone app uses the same settings as you would connect to another machine. The only reason I am asking about it is that sometimes I need to use RDP from my phone to look something up for work. I know I could probably do a VPN tunnel and just connect that way but i want to try to take that extra step out of the process.

note: I'm trying to connect from my Iphone's 3g connection. I am not connected to any wifi when attempting this.

Thanks for any insight.

A few things to think about... What OS are you trying to RDP into? Anything after Vista uses NLA by default, so try setting that to accept unsecure connections if that's the case. Can you verify that you can see the port open from your phone? I use Fing (available on iPhone and Droid), but just about anything should do.

Can you post the error message Mocha spits out? I use Mocha as well (albeit not to anything behind a monowall) and it usually gives you some idea of what's wrong when there are problems.