You need these in your UIS file.
[Vista.Shell]
Image=SkinName\vistashell.bmp
[Explorer.InfoPane]
Image=SkinName\explorer_infopane.bmp
Vista.Shell is the top bar (the one with Organize, Views, etc.) This appears to be what the bar2.bmp image is for. Of course, you can call the images any name you want.
Explorer.InfoPane is the bottom bar (the one at the bottom with the big icon and the file information.)
Does that help?