I backup my Iphone 4S through itunes but when I go to restore from backup it doesn't show my last backup it only shows my Iphone name

I BACKUP MY IPHONE 4S THROUGH ITUNES BUT WHEN i GOT TO RESTORE FROM BACKUP IT DOESN'T SHOW MY LAST BACKUP IT ONLY SHOWS MY IPHONE NAME EVEN THOUGH BEFORE ATTEMPTING TO RESTORE MY PHONE IT CONFIRMS MY PHONE HAS BEEN BACKED UP (SHOWS DATE AND TIME OF LAST BACKUP)

I HAVE TRIED UNISTALLING AND REINSTALLING ITUNES TO NO AVAIL