TD-W9980 Port Forwarding Help

[#1]

Hi All,
Hope someone can help.
Have upgraded my router to the TD-W9980 but am experiencing some issues with port forwarding to my IP cameras.
If anyone is familar with this router, i have gone into the forwarding menu, entered virtual servers and then entered my internal IP address for the IP camera plus the port it points to.  Still, however, the ports are closed.
Any ideas?  Is there anything else i need to do.
Appreciate any help with this.
Thanks!

[#2]

OK check a few things.
Can you connect locally to the ip:port you have opened. (e.g. if it is 192.168.1.100 and port 80 does entering 192.168.1.100:80 into the browser open the camera?)
The port will appear closed until the unit is running and the receiving port is up.
Check you have ENABLED it as well as entering it on the router.

[#3]

Thanks Hairy - i dont know what i did but all seems to be working now.  Thanks for taking the time to reply.  Cheers