I am an IT guy for a company whose owner has a Slingbox in his home. I have firewall access and so forth to our network, but not where the Slingbox resides. I have verified that we have outbound access on 5001 open, but the owner is not able to access his Slingbox from within our network. He uses the "Finder ID" to connect. The error 0x8007274C is what he receives when trying to connect.

He can, however, connect from any other internet connection he has tried. Nothing has changed on our access rules or anything that I can think of.  Another thread indicates replacing the router, but if I can connect from one location and not another, that should not be the issue.  

I'm pretty out of the loop on the Slingbox; can anyone point me in the right direction on how to troubleshoot this?