On a pair of Bruno Maglis I have, the leather part on the inside of the shoe that touches your heel ends close to mid-foot, and it goes down to another leather part. The part under the heel seems to be glued down to the front part, and this seems to be coming up, folded back. It annoys me when I wear them and walk. What kind of adhesive should I use to glue this back down, or how should I fix this? A similar thing is also happening on the side of the insoles of another pair of shoes I have.