OpenGL Render - Not all textures show

Not sure what I am doing wrong but when I render a movie some of the textures disappear. The blend file can be seen here: https://dl.dropboxusercontent.com/u/4864857/BlenderForum/Minecraft2.zip and the resulting video here: https://dl.dropboxusercontent.com/u/4864857/BlenderForum/0001-0400.avi.

I am using the following settings:
Viewport Shading: Rendered (and it all looks good)
Output: H.264
Dimensions: HD720P
Display: Only Render
Shading: GLSL

I need some help. What I am wanting is a process that I can use with my students so that they can quickly render a textured movie.

You haven’t included any textures in your blend file !!

Pack them all in your blend file (File / External Data menu)

Tried that but kept being told that it can’t find them… which is strange as I can see it in the preview modes