NAT setup for Back to My Mac`

[RonHerrmann]

Sorry - I've searched & searched, but the number of threads is too vast, so I am posting this question.
The "Back to My Mac" (iCloud) setting on my MacPro (Lion OS X v.10.7.4) repeatedly shows the following notification:
"Back to My Mac may be slow because NAT Port Mapping (NAT-PMP) or Universal Plug and Play (UPnP) is turned off on your router. Turn on NAT-PMP or UPnP. See the documentation that came with your router for instructions."
I've read the manual, and it seems that NAT is built in to my FVS318v3 (unless I've screwed up the settings somehow), and I see no chapter or section that describes how to turn NAT (or NAT Port Mapping) on or off.
All my Macs (12 - some connected via a Netgear switch) are able to access the Internet without problems, so that would further indicate that NAT is working properly.
Am I looking in the wrong place (manual OR router log-in window)?
Is there a way to determine whether my Mac is just mis-'diagnosing?'
Any suggestions, anyone?
Even a link to the correct thread will be appreciated.
Thank you in advance for your help.

[jmizoguchi]

will never work with fvs318.

http://forum1.netgear.com/showthread.php?t=1461

under enterprise I have posed 2years go on NAT-PMP on back to mac issues