They should be visible even with the wrong texture. You could create a jpk from the joe files and load it into blender(you'll need a lot of ram > 2GB for the whole track though) to see if the meshes are loaded properly.
If you are getting the same error it means that you are creating th jpk the wrong way. Your jpk contains relative paths to joe files. The list.txt references file names not relative paths. Try creating the jpk from within objects directory. Or try this one: http://www.megaupload.com/?d=DKP11UL6