I have a dyndns account that works for many things - but when I tried with Obi - it actually brings up some of the Obihai web page, but I'm getting
"502 Bad Gateway - REsponse Error, a bad response was received form another proxy server or the destination origin server."
My local IP for OBI is 192.168.0.140 - in port forwarding, it is the only port 80 I have.
Some other port forwarding things for Sabnzbd and Sick Beard are working ok - so I know the port forwarding on router is ok.