Problems Applying Icons

I'm having a problem applying icons with Icon Packager to external hard drives.

I am using Windows Vista and have two external drives. One labelled M for my media and another labelled z for documents and other stuff.

When I apply an icon package the program will change all the icons for all my drives except Z. The folders on Z are Documents, Favorites, Links and finally Downloads.

Anyone got any ideas what the problem may be.

Edit: The Icon Packager program will apply the icon set to all folders within Documents, Favorites, Links and Downloads but not to the Documents, Favorites, Links and Downloads folders themselves.