Specularity Not Working as it Should

This is a repost from what I have just posted over on the bd forums -

In the course of making a number of placeables I accidentally discovered that what it says in the NwN EE Wiki, specifically in the Standard material inputs article, is wrong. For months now, I have religiously made sure that my spec maps are 8 bit greyscale. I have also struggled to get any sort of reflectivity from the placeables that I worked on. Then, just tonight, I made a serendipitous (means happy accident) discovery. In my attempts with spec maps I have used the gimp to brighten these maps (its the only image editing software I have access to that will save 8 bit greyscale TGA files). In order to make them even paler, I tried loading some spec maps into paint.net. After that I saved them and tried them, forgetting that paint.net can only save in either RGB or RGBA. Upon testing I found the glossiness of the selected placeables was spectacular. Afterwards, I realised that the spec maps were in the “wrong” (24 bit, RGB) format and used the gimp to convert them into the “right” (8 bit, greyscale) format. Upon re-testing, I found that the glossiness had vanished again. Reverting them to 24 bit RGB restored it.

Conclusion - Either spec maps are supposed to be 24 bit RGB (not 8 bit greyscale) or there is a bug.