CS5 Refine Edge Problems

[mant01]

Ive been trying to cut some images out and use the refine edge for the hair. The problem is it seems to lighten the area painted on and when used around the eyes it really messes it up. Any idea whats wrong? Ive followed guides but it doesnt seem to happen on them?

 

[Kerioak]

Just out of curosity as I often have a similar problem how different a colour/light/dark is the background you are trying to remove ?

 

[mant01]

Ive tried a few different ones with from light to dark backgrounds and still it seems to lighten the image and make it go kinda see through when I touch up an area to add the surrounding detail.