Many thanks lostinthewoods,
I believe the same process is relevant.
I went through all procedures myself as it was becoming very annoying seeing these message screens pop up every fifteen minutes or so.
I arrived at the cause which was my Humax Freesat Box. The Humax Box was receiving update messages that an update was installed in the Freesat Box (Apple Player!).
This in turn sent a message via pulse to the TV.
I'm about to do a reverse test to see exactly what should be done to avoid this screen. I believe it will be the deactivation of the HDMI control on the Freesat Box itself.
I'll keep the forum updated accordingly as to my findings.
Many thanks for the direction to the post which helped greatly in confirming my my thoughts.
All the best to you!
Have a Merry Christmas with great TV viewing!
