Iphone touch lock

My iphone started acting very strange about week ago.
When i switch screen on everything works.. until i don't touch it for 1-2 sec. then screen will not respond to touch anymore.. all the rest of programs and other buttons are working fine..

And when i switch screen off and on again.. it will let me again use the screen until i don't touch it for 1-2sec..

Would be really great if anyone can help me find solution to it..

I tried already rebooting, rest all settings and even restored it to 1.1.1
Nothing.. all the time the same..

Best,

I.