Update..Playstore is installed and been updated to latest version that runs on devices, and rebooted as suggested.
Have tried disabling Playstore and can see that it does affect App operation and re-enabled App works to the point at which they go off to pull through video from the servers - this includes YouTube, Morpheus TV, Terraium and my IPTV client apps. At that point they all hang and don't pull through anything. I've even tried a direct HDMI connection to TV rather than through my Amp but that hasn't done anything.
Any more ideas ?