Forget setting up the USB/RS232 adapter you just need to set up the TV.
1. fire up the setup wizard (sarah) from the advanced menu, ignore the section on TV's and go through until you get to the 'Any other AV equipment page',
2. at this point add a device find the device type as TV-LCD/Plasma etc. then Manufacturer, then pick the template from the list.
3. continue through until you are finished and sarah want to reload.
4. after reload go into webadmin > AV equipement find the newly added TV and set the com port to PCI........... (whatever this is), depending what you have plugged in will depend what is on this list.
5. set the room to where it is and hit update, then reload the router.
6. fire up the setup wizard angain and let sarah set the device pipes for the TV.
Now try it
My Aquos and LG is working right now although each one has issues that I need to resolve.