Well you run your games in 4K on a "Haswell" system. :D:D:D my bad.
That hadnt even crossed my mind, I only had a new 4K TV delivered yesterday so it has always just been set at 1080/60 not 2160/30
Kodi had autodetected and switched over to 4K, I've just switched it back to 1080 at 60 and everything is fine and working.
apologies for all the hassle. feeling at bit silly now.
Cheers for all the help.