self-illum/bumped specular texture problem

Hi, I'm using self-illuminated/bumped specular shader and noticed that while the doc says the emit-map should be the normalmap alpha channel. So what does Illumination texture stands for? Moreover, trying to change the alpha channel for both the illumination and normalmap does not seem to achieve concistent changes in the self-emission. It seems that the emission is influenced also by the RGB part of the illumination texture. Tthe parameter 'Emission (lightmapper)', if changed, does not seem to have any noticeable effect on the result. Any hint about that? Many thanks, Andrew