I hope that this thread hasn't run its course, but I am having similar problems to the original post in getting Viera Cast, and I'm not sure how the previous posts might help me, as they are going a bit beyond my IT know-how.
I have a Panasonic TX-P42G20B and have gone through the setting up procedure for veira using an ethernet connection, and the connection test comes up all ticks. But when I press Viera Cast the message comes up that, 'connection to the sever failed (006)'. I rang up my broadband provider, I have BT Home Hub 2, and they said that, to test the router, if I connect the ethernet cable to my laptop it will over-ride the wireless connection, so if I remain connected the internet the router and cable must be OK; it is a TV problem (I have spoke to several BT advisors, none of them knew of Viera: do any of them know their stuff?).
I rang Panasonic and they said if the connection test was OK it must be the router. I rang John Lewis, where I bought the TV. The guy there really tried to help me although he hadn't come across this problem and thought that I might need to do something to the router (neither BT nor panasonic mention this). I guess this is the problem, but don't know what would fix it. Any suggestions?