Q:

Unity will not boot 12.04

I switched to GDM and restarted.  No problem.  Waited several days and my system is working well, except for a minor bug in Gnome 3.4.  I install Ubuntu Tweak and make a few tweaks.  Reboot and all is well.  I run Cleanup in Ubuntu Tweak and clean everything up except for the previous kernel.  Reboot and for the third time installing 12.04, Unity will not load.  Log out and try Gnome.  Gnome 3.4 will not load but Gnome classic does.  The ATI video card is humming away.  
I pull up a terminal and try Unity --reset, but I get numerous error messages and then it freezes.
Is there any way to fix this issue.  Third time this has happened - I should have left it alone and not installed Ubuntu Tweak.  Any help would really be appreciated.
See my previous post - only difference is GDM was installed before using Tweak

A:

I was told to do this, although I am answering my own question.  Ubuntu Tweak seems to mess with the fglrx driver. I was about to give up hope but decided to remove the driver and reboot. Still no Unity or Gnome 3.4. I installed the ATI Proprietary Driver. It took 3 trys as the first two installs insisted that fglrx was still installed. 3rd try installed flawlessly. Reboot and Unity and Gnome 3.4, better than ever. This is an issue I have seen on Google numerous times. Beware of Cleanup Janitor if you have an ATI card. It will cause you trouble. I have gone back to lightdm and it works perfectly. 

