got the same problem here...
- I did a clean install of ubuntu 11.04.
- Installed all updates.
- Downloaded the nvidia driver 270.41.06.
- Stopped the X Server
- Installed NVidia Driver
- Stared X Server
After reboot, i get blank screen...
So I did clean install again without updates. This time I tried the recommended nvidia driver from "Additional Drivers" section. After installing and rebooting OS, i get the same problem... blank screen.
I got an Nvidia GeForce GTX 460