I happen to have the Netgear MR814 and "Port Forwarding" is indeed the correct way to accomplish this task. Are you running a SOFTWARE FIREWALL on the PC you're forwarding ports to? If so, that may be blocking the calls. If not, lets give others a chance to chime in on this one. BTW, I didn't find any info on Netgear's web-site in the FAQs.
*EDIT* One other thought.. Are you attempting your ident query from within your LAN but to your REAL (i.e. EXTERNAL) IP ADDRESS? If so, that won't work. You'll need to attempt your ident query from outside your LAN. My buddy had the same problem w/ FTP. He thought the router wasn't forwarding FTP requests; however, he was attempting to FTP to his server's EXTERNAL IP ADDRESS from within the Netgear MR814's LAN. That simply confuses the router.