I have another problem running my code on a wildcat realizm 100. The driver exports the WGL_ATI_pixel_format_float extension, but creating a floating point buffer fails while finding a pixel format.
I choose following pixel format:

WGL_DRAW_TO_PBUFFER_ARB, true,
WGL_SUPPORT_OPENGL_ARB, true,
WGL_DEPTH_BITS_ARB, 24,
WGL_RED_BITS_ARB, 32,
WGL_GREEN_BITS_ARB, 32,
WGL_BLUE_BITS_ARB, 32,
WGL_ACCELERATION_ARB, WGL_FULL_ACCELERATION_ARB,
WGL_BIND_TO_TEXTURE_RGBA_ARB, true,
WGL_ALPHA_BITS_ARB, 32,
WGL_STENCIL_BITS_ARB, 8,
WGL_PIXEL_TYPE_ARB, WGL_TYPE_RGBA_FLOAT_ATI,
0,0,

wglChoosePixelFormatARB returns without error, but it finds only 0 pixel formats. On my ATI with the same code the driver returns a pixel format. My nvidia path with NV_float_buffer also creates a pbuffer without problems, so what do I have to do, to create a floating point pbuffers on a 3dlabs realizm 100? A normal pbuffer is created without errors, but floating point pbuffers fails always