What EXACTLY is the problem? I assume Tivo desktop can't connect to the Tivo unit?

There are several things you can try. I would be to try and "ping" the Tivo unit or use your web browser to see if it is reachable off your PC.

You mention your corporate firewall, but unless that firewall software is running on your PC I don't see why the firewall at your firm could block you at home. When you are at home are you always connected to the firms VPN? Have you tried disabling the VPN software?

Try and find the IP address of your Tivo unit (Tivo button > Messages and Settings > Settings > Phone and Network > In the top right you'll see your IP. Make a note of that).

Now on your PC click START then RUN and enter CMD. You'll now be in "dos". Type

ping <ip address here>

It should return "reply from........".

Now try the webbrowser too: type https://<enter ip address here> You should get a screen asking for a username and password for the "Tivo DVR".

If neither of these options work, then you do indeed have a network problem and something on your PC is blocking it, we can try further from there...