The latest version of Blender 2.63.22 r50890 does not respect weight map values in the Pinning feature for Cloth.

Maps with 100% values in build 2.63.0 r46461:46487M do not get affected by the cloth simulation.

In the attached file you will see the geometry falling using the RC2 build, where as in previous builds the animation is respected due to the weight values in the "SoftBody" vertex group used under "pinning".

If the Stiffness: value is pushed to 50, the object does not fall anymore, but the 100% vertices are still affected.