It's a very good suggestion jazzymjr, it works on empty image too, but you must change the extension from bmp to tga in code editor
I ran across a problem once while making a blind that had a completely transparent image. It was while using layers on the start panel. The base layer was completely transparent, and the layer over it had something on it. The result was that in 64 bit systems, that part did not show at all!
I highly recommend using the tip Jazzy mentioned. You can run across some weird things with totally transparent images.