waseem@waseem:~$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree... Done
You might want to run ‘apt-get -f install’ to correct these.
The following packages have unmet dependencies:
  fglrx-control: Depends: xorg-driver-fglrx but it is not installed or
                          xfree86-driver-fglrx but it is not installed
  xorg-driver-fglrx-dev: Depends: xorg-driver-fglrx (= 6.8.0-8.8.25-0ubuntu11.1) but it is not installed
E: Unmet dependencies. Try using -f.

===============================================================================================

waseem@waseem:~$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree... Done
Correcting dependencies... Done
The following extra packages will be installed:
  xorg-driver-fglrx
The following NEW packages will be installed:
  xorg-driver-fglrx
0 upgraded, 1 newly installed, 0 to remove and 97 not upgraded.
56 not fully installed or removed.
Need to get 0B/3185kB of archives.
After unpacking 10.2MB of additional disk space will be used.
Do you want to continue [Y/n]? y

Preconfiguring packages ...
(Reading database ... 260214 files and directories currently installed.)
Unpacking xorg-driver-fglrx (from .../xorg-driver-fglrx_6.8.0-8.8.25-0ubuntu11.1_i386.deb) ...
dpkg-divert: `diversion of /usr/lib/libGL.so.1 to /usr/lib/fglrx/libGL.so.1.xlibmesa by xorg-driver-fglrx' clashes with `diversion of /usr/lib/libGL.so.1 to /usr/lib/nvidia/libGL.so.1.xlibmesa by nvidia-glx'
dpkg: error processing /var/cache/apt/archives/xorg-driver-fglrx_6.8.0-8.8.25-0ubuntu11.1_i386.deb (--unpack):
 subprocess pre-installation script returned error exit status 2
Errors were encountered while processing:
 /var/cache/apt/archives/xorg-driver-fglrx_6.8.0-8.8.25-0ubuntu11.1_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)