Relative Image Reference Not Working

I am working on a KMZ archive that is giving me issues when referencing the images. The structure of the KMZ is simple. doc.kml is the only kml inside of the archive. There is a folder named "files" that contains two images (pic1.bmp & pic2.bmp) within the archive. I place these items into a zip folder and rename it to .kmz to create a KMZ file (for those wondering - yes this is the proper method for doing this). Within the doc.kml the images are referenced <img src="files/pic1.bmp"> <img src="files/pic2.bmp"> This is my understanding of the proper way to create a relative reference for a KMZ when loading media within the KMZ. However, the images fail to load. This will work if the images are in the same directory as the KMZ archive and they are referenced as <img src="pic1.bmp"> <img src="pic2.bmp"> However, this is not an option as the whole point of building the KMZ files in the manner originally described is so they can easily be shared via e-mail. I should only have to send the KMZ archive - not all the supporting media. Additionally, I need to use HTML because I'm also using some javascript to permit mousewheel zooming and clicking to toggle between the two images (that code not supplied as not necessary to resolve this specific issue - the images will not display). What am I missing?