A lot of times when nvidia users use the restricted drivers they get a message after rebooting stating that Ubuntu has been launched using low graphics mode. This has really frustrated many users that they gave up hope on Ubuntu. I recently installed Ubuntu 9.04 Jaunty and when I activated my drivers, I got that annoying message. Luckily, I found a bitter-sweet solution for it.

1. Boot up Ubuntu
2. Open the terminal
3. Type in sudo dpkg-reconfigure -phigh xserver-xorg 
4. Reboot Ubuntu 

Hopefully, if everything went smoothly you should now be out of the low graphics mode, though, this does not solve the problem; it is merely a work-around. OpenGL and 3D acceleration is now disabled. To solve the problem, you should post a new thread in the Ubuntu forums since this problem is unique to each individuals computer.