ok, I got things working. I have a netgear router. I deleted the port forwarding configuartion that was already there from when I set it up with my iphone 3gs. The web based auto configuration on the sling web site then was able to create a new config and
I can now stream audio and video from the sling box classic to ios 5 iphone 4s.
I'd like to say thanks to the slingbox folks but since I had to figure this out myself and the only thing they would tell me was to buy a new box or pay them money to get support for something they should just tell you well......