Okay in Blender 2.63, the various action actuators like Armatures, F-curves, and Shapes have been combined into single Action actuator. I have made two equivalent shape actions that scale the mesh, one uses a bone and the other, (preferred,) works directly on the mesh.
I can play both deformations in the object window using the Timeline editor, so they are both recorded correctly, they both appear in the Dope Sheet and both are available in the actuators list of available actions. However, when I connect them up to a collision sensor in the BGE, only the action using a bone appears to work.
Has anybody any ideas?
Stupid me, I got it working just after posting this. It was a problem with the physics, (blush.)