Doom 3 error during init "video card/driver combination" with softmod: HELP!

[bungee]

Hi!

I have a 9500np softmodded (Cat 4.9) to 9700+ and I downloaded the Doom 3 demo. I can't start it because it says this:

DOOM 1.0.1280 win-x86 Sep 10 2004 16:46:16
2163 MHz AMD CPU with MMX & 3DNow! & SSE
1024 MB System Memory
128 MB Video Memory
Winsock Initialized
Hostname: guderian
IP: 192.168.0.2
doom using MMX & SSE for SIMD processing
enabled Flush-To-Zero mode
[...]
X..GL_ARB_multitexture not found
X..GL_ARB_texture_env_combine not found
X..GL_ARB_texture_cube_map not found
X..GL_ARB_texture_env_dot3 not found
X..GL_ARB_texture_env_add not found
X..GL_ARB_texture_non_power_of_two not found
X..GL_ARB_texture_compression not found
X..GL_EXT_texture_filter_anisotropic not found
X..GL_EXT_texture_lod not found
X..GL_1.4_texture_lod_bias not found
X..GL_EXT_shared_texture_palette not found
X..GL_EXT_texture3D not found
X..GL_EXT_stencil_wrap not found
X..GL_NV_register_combiners not found
X..GL_EXT_stencil_two_side not found
X..GL_ATI_separate_stencil not found
X..GL_ATI_fragment_shader not found
X..GL_ARB_vertex_buffer_object not found
X..GL_ARB_vertex_program not found
X..GL_ARB_fragment_program not found
********************
ERROR: The current video card / driver combination does not support the necessary features.
********************
Error during initialization
Shutting down OpenGL subsystem
[...]

Do you have any idea what could cause this?
Thank you very much!

 

[bungee]

Z-buffer 16 bits

Ok, I found that what prevents Doom to start is that I set z-buffer forced to 16 bits in display properties for OpenGL. This is needed to remove the heavy chessboard effect coming with the softmod. It was successful with every game I tried so far, like Call of Duty which is using OpenGL partially.

Do you think there is a way to work around the problem and start Doom3 with 16 bits z-buffer? Thank you