After posting the bug report I received this tip:
"I'm having the same problem here. I'm using VBox 4.0.8 on OpenSuse? 11.04, and one of solution that is working, try to install old version of guestAdd, 3.2.1.
After that you can enable 3D, and you will not have any problem."
So I installed Guest Additions v3.2.12 and enabled the 3D. The FEM program preprocessor Salome-Meca worked fine and previous issues with rendering element and node numbers in the meshing module are no more. Thus far no other issues have cropped up with this older Guest Additions version with VBox 4.0.6.