I added some custom buttons to iDVD 4 following the creativemac tutorials(which are for iDVD 3). While the buttons do appear in the button menu, selecting them produces no result. I notice that iDVD 4 has .pox folders for each button, which iDVD 3 may not have had. Nagel's tutorials didn't show them.

Can in fact custom buttons be added? If so, do I need to create the .pox contents (which appear to tiff files like the buttons themselves, but with code names)? And if I do, what is the naming convention? Would I be better off customizing an already exisiting button that I don't think I'll use?