Eyetv configuration

I use Evetv on my iMac to watch TV and I was able to access this service away from home on my iPone with the app My Eyetv. This has stopped working, the problem seems to be that my NETGEAR C3700 won't let the connection through. The Eyetv program automatically configures the router but now it seems it can't for some reason. When I turn off my firewall everything works. The program is listed in my allowed programs. When I try to port forward the port 2170  (which EyeTV uses) the NETGEAR C3700 gives me an error that that port is already being configured.

 Can someone please help me, I use this app a lot when traveling and can't figure out why it was working and now doesn't. The EveTV support has helped but concluded it is a problem with my router even though it is listed as compatible.