SKYHD SIGNAL SWICH OFF PROBLEM ? WITH NEW SONY KDL 40W4500

Hi Can Anybody Help ???

 Pulling my hair out

Just bought New Sony Bravia KDL 40W450 Tv

Great TV but I seem to have a problem with my SkyHD box thru the HDMI

After about an hour or so i lose the Sky picture and it reverts to a blank screen just showing the HDMI input name tag in top left corner of the screen, the only way of getting the picture back is to change to another input say via AV and then go back to HDMI1 or switch of the sky box and restart and then the picture returns after a variable amount of time watching though it will do it again !!!!

 Can anybody explain !!!

Is this the HDMI pin 13 problem I have seen on other forums

 Help would be most appreciated