Material texture does not resize

[Flion]

I'm watching Chaos group courseware. In lesson 3, Main modules, at 14:10, there's a material applied to a wall which has a scale that has to be corrected in sketchup for the scale. However the texture is not applied as a diffuse but as a bump map. One has to find a bump map, click on the eyeball and then the texture size can be fixed in sketchup. Tutorial than says to click on the eyeball again and turn off the visibility of the material.
As soon as I turn it off the texture scale goes back. Am I doing something wrong?