I put set_color_depth() in because the map loader generates allegro BITMAP's and converts them to OpenGL textures.
I am using AllegroGL version '0.2.5 CVS 20050308', it's the DevPak that I got in Dev-Cpp. I didn't notice it was so old when I installed it. I'll see if I can get a newer version.
Not got a clue about the graphics card, but it's onboard so it's probably i810.
Sirocco, it's not a 'proper' problem with the code, as it compiles and runs fine on FreeBSD and Debian. I just can't make it work in school or on friend's computers.
Installed AllegroGL 0.4.1. Same problem. Problem might be that it's using the old one. I'll try getting rid of it...
Finally got it working with -lagl_s. Problem over!