(SOLVED) Can't hear recorded track !!

Hi
OK I record a guitar piece on track one, it lasts twelve bars, after eight bars I make a mistake, I then, using the smart tool
delete not all the track just back to the mistake, then I take the timeline back another two bars, arm the track ready to record again
but I can't hear the two bars before, just the drums, it's like my monitors have gone, any ideas ?
 
Thanks
John
I was in comping mode !!!!!!!!