So here is the answer:
Step 1:
Delete /var/cache/apt/archives/
sudo apt-get clean
Step 2:
Purge fglrx
sudo aptitude purge fglrx
If you get error that looks like:
dpkg-divert: mismatch on package
when removing `diversion of /usr/lib/libGL.so.1.2 to /usr/lib/fglrx /libGL.so.1.2.xlibmesa by fglrx'
found `diversion of /usr/lib/libGL.so.1.2 to /usr/lib/fglrx/libGL.so.1.2.xlibmesa by xorg-driver-fglrx'
dpkg: error processing fglrx (--purge):
subprocess installed post-removal script returned error exit status 2
Processing triggers for ureadahead ...
Errors were encountered while processing:
fglrx
you need to delete fivert linsks:
sudo dpkg-divert --rename --remove /usr/lib/libGL.so.1.2
sudo dpkg-divert --rename --remove /usr/lib32/libGL.so.1.2
and retry purging:
sudo aptitude purge fglrx
Step 3:
Reinstall fglrx
sudo aptitude install fglrx
Step 4:
Rebuild xorg conf
sudo dpkg-reconfigure xserver-xorg
After that I got bad resolution. Answer is in the following post.