I am on 1.92 final + patch 1 and Unity 4.1.2. Instantiation is handled through PoolManager 4
CreateBoxCollider is true on the prefab, and the ColliderType in the collection is set to BoxTrimmed.
Currently I set the sprite and collider after instantiation through:
((tk2dSlicedSprite)(this.GetComponent<tk2dSlicedSprite>())).scale = new Vector3(xfactor, yfactor, 1);
((BoxCollider)(this.GetComponent<BoxCollider>())).size = new Vector3(width, height, 0.2f);