Very Computer

Maybe I'm just being stupid but I don't know why this is happening. I have
a #9 771 card which uses the IBM RGB524 Ramdac. When I uncomment this line
in my svgalib.config

        Ramdac IBMRGB52x

svgalib reports

        svgalib: s3: Assuming normal VGA DAC.
        svgalib: Using Normal VGA RAMDAC.

However, if I uncomment any of the other ramdac lines, it uses them (which
is of course not what I want). I'd like to have more modes than are
available with standard VGA; is there anything I can do?

Thanks
Nick