Comment 1 for bug 134918

I can confirm this using Gutsy Tribe 5 and an Nvidia GeForce FX 5600XT. When ticking the box to enable NVIDIA Accelerated graphics driver I received the message "The software source for the package nvidia-glx is not enabled". Looking at Software Sources, I saw that all repositories was ticked. I unticked and ticked them all and closed the window, which then reloaded the package lists and allowed me to install nvidia-glx.