m3grant wrote:

You're not gonna believe this but I gave the screen a good polish with some furniture polish and the problem went away! Doesn't make any sense at all but its been fine for a week now that its clean. Prior to this it was playing up every single day.

Maybe some grease on the screen causing a false "finger contact" of sorts. My Blackberry refuses input on the touch screen from time to time, a good wipe on the jeans and it's all good again. 

"Roads ? Where we're going there are no roads." Back to the future.