The Collaborative International Dictionary of English v.0.48:

Sticking \Stick"ing\,
   a. & n. from Stick, v.
   [1913 Webster]

   Sticking piece, a piece of beef cut from the neck. [Eng.]


   Sticking place, the place where a thing sticks, or remains
      fast; sticking point.
      [1913 Webster]

            But screw your courage to the sticking place,
            And we'll not fail.                   --Shak.
      [1913 Webster]

   Sticking plaster, an adhesive plaster for closing wounds,
      and for similar uses.

   Sticking point. Same as Sticking place, above.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sticking point
    n 1: a point at which an impasse arises in progress toward an
         agreement or a goal