>The use of the External reference is used as a means to pull referenced files into your application, which can be done through indirection or macro substitution. It is a positive technique to insure external files will be seen as a part of your project without concern for problems with paths, etc. It is one of the things I have used for every project since I cannot remember. Also, it is something I have not seen in the literature, but then I have not read everything! :)
Yup, the mystery here is that I have about 40 images on the menu and I had to put only 4 external references to make it work. Also, where it was not working, the menu items were exactly as other menu items where it was. So, this is really a bad bug. I spend about four hours last night on that one.