Port Forwarding should not be needed if your DNS is connected to your NG gateway modem/router.
If PF is needed, uPnP should be disabled.
Ensure you are up to date on Java.
What browser are you using?
Try Opera or FF? If IE 8 or 9, set compatibility mode and test again.
Test your Gateway with Firewall settings OFF as a temporary test to see if this works.
I recommend contacting Netgear about any configurations, if needed, on the NG gateway.