I have a dell inspiron 15r se. Step by step, I wanted to upgrade the system from 11.10 to 13.04. Up to 12.10 everything was alright, it was working very well,
When i did
sudo do-release-upgrade from 12.10 to 13.04, after the upgrade unity was not working, I had only desktop visible, no menu on top or left (i am not sure how they are called). I had exactly this.
What I tried
Of course I tried resetting unity, enabling unity plugin in compiz, etc, but nothing worked.
At this moment I don't really remember what I have done (I tried many different things like until 2 am in the night, i can't recall all) and now what I get is the "Low Graphics Mode" just like in here. My graphics card is ATI, so I tried the solution offered here, and absolutely nothing changed.
I also tried installing linux-headers-generic, also linux-headers-'uname -r', adding a symbolic link for version.h (because it wasn't there, i did something like that) but none of them worked.
Starting using one of the old kernels (selecting them from GRUB) does not work either, each one of them also go into low graphics mode.
Here is the output from my /var/log/Xorg.0.log
Any help is appreciated!