No Unity 3d option on the login screen

I upgraded my ubuntu to 11.10 on day one but the unity 3d is not there as an option. I have User Defined, Recovery Mode and Ubuntu 2D.

I've done this test /usr/lib/nux/unity_support_test -p and all results are green YES. Here's the result

OpenGL vendor string:   ATI Technologies Inc.
OpenGL renderer string: AMD Radeon HD 6700 Series 
OpenGL version string:  4.1.11005 Compatibility Profile Context

Not software rendered:    yes
Not blacklisted:          yes
GLX fbconfig:             yes
GLX texture from pixmap:  yes
GL npot or rect textures: yes
GL vertex program:        yes
GL fragment program:      yes
GL vertex buffer object:  yes
GL framebuffer object:    yes
GL version is 1.4+:       yes

Unity 3D supported:       yes

Clear your apt cache

sudo apt-get clean

Install Ubuntu desktop and force a re-install

sudo apt-get install --reinstall ubuntu-desktop

This will install all the packages necessary from the desktop to run, you should see Ubuntu as an option next time you reboot.

I had a similar problem when running the beta version of 11.10. What I did was go into the software center and search for Unity, uninstall then re install it with all the add-ons listed.

If that doesn't work, try running "sudo apt-get update" and "sudo apt-get upgrade".