Hey peeps! Its me again with another skinning question.

In certain section during my skin makeing process, images that i previously imported become darker. This happens mostly with the Buttons, Start menu, and explorer backgrounds. I only have to reimport the image.....but this takes up time. It useually happens more than once? I mean i will see that the image is darker, i will reimport, and then keep working on the skin........then like an hour later or so it will have happend again? I then will have to go back and reimport? Any help with this?

I dont know if this is normal? I would think that i happens to everyone but...? It happens allot? Is there ay way to stop it from happening, such as changing settings?