Grasshopper1980, you may still want to check your Transformation tools(clear button that turns greenish when you mouseover, at the top left corner of the texture in material lab) and make sure they are not reading an x,y,z, value that is making your bumps dissappear. As I have recreated a scenario that makes the bumps not work with some of those values, ie. set them to 0 or a low value to start, cause changing a texture there, in lab, doesn't alter a transformation value(unless you change objects in scene).