I managed to take a look at GLSL and multi-texturing for a few minutes.  Here's what I found:

1) ARB_fragment works exactly as expected with multiple texture units in GEM
2) GLSL does not work with the same GL setup commands in GEM
3) Apple's ShaderBuilder does not work with Anton's shader nor any example shaders I tried with multiple textures
4) Shader builder works exactly as expected using ARB_fragment

This is with a G5 and Nvidia GPU.  I won't get back to this until Monday, but I suspect that some setup calls need to be updated or changed to match what the drivers want in order to access multiple textures.

For what it's worth, I only use ARB_fragment shaders in my own work.   They seem to work better and more efficiently.  I can post some shaders next week if anyone is interested.

On 7/5/07, vade <doktorp@mac.com> wrote:
sorry. let me clarify. long work day does not make me clear.

switching texunit switches the textures. however, mixing only occurs between unit 0 and unit 0. Not between unit 0 and 1.

this is with Cyrille's patch.

Thanks.