In my case I found that the 8800gts was not working due to a missing x-server module as reported in the Xorg.0.log. The required file is included with Nvidia's driver-package, but there's no trace of /usr/lib/xorg/modules/libwfb.so* in any ubuntu-packages. I.e. it seems to be a build/packaging issue, and that the file simply should be included in the nvidia-glx-new package. The X-server works, with eye-candy and all, using the driver in nvidia-glx-new if the missing file manually extracted from nvidia's package and copied into /usr/lib/xorg/modules.
In my case I found that the 8800gts was not working due to a missing x-server module as reported in the Xorg.0.log. The required file is included with Nvidia's driver-package, but there's no trace of /usr/lib/ xorg/modules/ libwfb. so* in any ubuntu-packages. I.e. it seems to be a build/packaging issue, and that the file simply should be included in the nvidia-glx-new package. The X-server works, with eye-candy and all, using the driver in nvidia-glx-new if the missing file manually extracted from nvidia's package and copied into /usr/lib/ xorg/modules.