If you are using Warcraft3 Image Extractor, search for the skin that your using and it will give you everything to do with it (buttons ect) this should allow you to edit all of the skins you need.
IDISacredIDI
p.s. Dont have WC3 IE? Follow the link in my siggy!
Ah I get what you mean. Weid it usually works, try removing your skin from the map then adding it again. If that doesnt work try adding your skin to another map and see if it works their.