Index: src/renderer/r_state.c
===================================================================
--- src/renderer/r_state.c      (Revision 15634)
+++ src/renderer/r_state.c      (Arbeitskopie)
@@ -39,6 +39,10 @@
        if (texunit == r_state.active_texunit)
                return;
 
+       /* not supported */
+       if (texunit->texture >= r_config.maxTextureUnits + GL_TEXTURE0_ARB)
+               return;
+
        r_state.active_texunit = texunit;
 
        qglActiveTexture(texunit->texture);
@@ -418,6 +422,8 @@
 
        r_state.texture_texunit.texture = GL_TEXTURE0_ARB;
        r_state.lightmap_texunit.texture = GL_TEXTURE1_ARB;
+       r_state.third_texunit.texture = GL_TEXTURE2_ARB;
+       r_state.fourth_texunit.texture = GL_TEXTURE3_ARB;
 
        R_SelectTexture(&r_state.texture_texunit);
 
Index: src/renderer/r_state.h
===================================================================
--- src/renderer/r_state.h      (Revision 15634)
+++ src/renderer/r_state.h      (Arbeitskopie)
@@ -50,7 +50,9 @@
 
        /* multitexture texunits */
        gltexunit_t texture_texunit;
-       gltexunit_t lightmap_texunit;
+       gltexunit_t lightmap_texunit;   /**< e.g. used for lightmaps in the battlescape */
+       gltexunit_t third_texunit;
+       gltexunit_t fourth_texunit;
 
        /* texunit in use */
        gltexunit_t *active_texunit;