add the following lines to 
..../Planeshift/data/config/gldrivers.xml
in the end of the rules section

    <!--
      * 2007-04-24: S3TC support in Mesa DRI R200 is broken.
                    (Linux stock OpenGL drivers on Slackware)
                    Since S3TC may also be used through generic
                    compression formats, disable TC completely.
      -->
    <rule description="Disable texture compression for Mesa DRI 200">
        <conditions fulfill="all">
          <regexp string="renderer" pattern="^Mesa DRI R200" />
          <regexp string="glversion" pattern=".\.. Mesa 6\.4\.." />
        </conditions>
      <applicable>
        <usecfg>disableTC</usecfg>
      </applicable>
    </rule>


    <!--
      * 2007-04-26: 
	OpenGL vendor string: NVIDIA Corporation
	OpenGL renderer string: GeForce 6600/PCI/SSE2/3DNOW!
	OpenGL version string: 2.1.0 NVIDIA 97.55

      -->
    <rule description="Disable VBO on GeForce 6600">
        <conditions fulfill="all">
          <regexp string="renderer" pattern="^GeForce 6600" />
          <regexp string="glversion" pattern=".\.. NVIDIA" />
	</conditions>
      <applicable>
        <usecfg>novbo</usecfg>
      </applicable>
    </rule>