Weird texture - gridshape - mesh problem

Hi folks,

I'm just getting into the gl 'paradigm', so I'm sure this is something basic, but the behavior of the patch below bewilders me. Every time I use the texture - gridshape - mesh combo the texture doesn't seem to cover the whole gridshape. It looks like there might be a couple of sides of the cube un-textured, but I'm not sure what's going on. I think the problem is pretty clear when you load the patch and turn it on (need to trigger the loadbangs though).

I get this on several computers, all of which are running Max 5.1.5 and Mac OS 10.6.4

Thanks in advance for any light on this weird gl thing.

Cheers,

Christopher