softbody not responding to goal weights (blender 2.40)

I just pulled down blender 2.40 and tried following a video tutorial on softbodies that someone was kind enough to send me a link to.
The demo consists of creating a mesh plane above the default cube, setting the weights of the vertices in the plane to zero except for a single strip along one side, assigning the vertices to a vertex group, enabling softbodies, using the vertex group as the goal, and turning on deflection on the cube.

what I get is a sheet falling down ontop of a cube. The goal weights seems to be ignored, ie the sheet isn’t pinned in place along one edge. I’ve got a .blend file I could supply as an example, but I don’t see anyway to attach it to this posting.

Eric Davies.