This is hardly a feature..
"The 71 and 96 series of proprietary nVidia drivers, as provided by the
nvidia-glx-legacy and nvidia-glx packages in Ubuntu 8.04, are not
compatible with the X.Org included in Ubuntu 8.10. Users with the nVidia
TNT, TNT2, TNT Ultra, GeForce, GeForce2, GeForce3, and GeForce4 chipsets
are affected and will be transitioned on upgrade to the free nv driver
instead. This driver does not support 3D acceleration."
