Internet TV problem

I have a Panasonic GT50 TV along with Pioneer reveiver LX85.

I connected the TV to my router for Internet access.However,when I press the Internet button on the Panasonic remote it loads fine and the screen shows,BBC iplayer,You Tube etc,etc but it changes back to the normal TV after 5 seconds.When I try again it keeps changing back to the previous TV programme after 5 seconds.

Any ideas?