How come i can connect to terminal service?

hi all,

I have two LANs which connected as a WAN through VPN
connection. There is a firewall at each site, and it set
to forward the Terminal service to a specified IP address
on the site which is a terminal service server.
The ip address range of the first LAN is 192.168.10.0-255
Terminal service server address is 192.168.10.2
public ip example : 202.100.100.89

The ip address range of the second LAN is 192.168.11.0-255
Terminal service server address is 192.168.11.2
public ip example : 203.49.56.90

I can terminal service to the server on the other LAN
using it LAN ip address. i.e from LAN 192.168.10.x to
192.168.11.2 However, when i try to use the public
gateway, it fails. i.e if i try to terminal service from
192.168.10.x to 203.49.56.90. Since the service is
forwarded, i imagine it should be alright. However, i
don't have any terminal service license running on the
terminal server, but i just use it for the administration
purpose.

Firewall setting:
this is put on the very top of the list and there is no
deny statement before it.
Allow access terminal service from * to 192.168.11.2

Any ideas?

Thanks in advance

Ken