boot - Ubuntu 14.04 booting stuck at loading screen

I have been using Ubuntu 14.04 for 6 months. Suddenly when I boot up the machine,
the booting process get stuck at Ubuntu's loading splash screen.

Loading screen img

I opened the terminal (Ctrl+Alt+F2) and commented out the GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" line from the grub and updated it,
so that I could see the booting process instead of the Ubuntu Splash screen.
From there, I found out that the booting process stops after the following
command:

* Restoring resolver state....       [OK]
* Stopping anac(h)ronistic  crom     [OK]

Any kind of help will be appreciated, many thanks!

EDIT:

After rebooting several times, it is seen that the boot does not stops at Stoopping anac(h)ronistic crom everytime. Sometimes it stops at

saned disabled; edit /etc/default/saned
* Restoring resolver state...                     [OK]
* Starting ACPI daemon                            [OK]
* Staring regular background processing daemon    [OK]
* Starting CPU interrupts balancing daemon        [OK]
* Stopping System V runlevel compatibility        [OK]

and sometimes at:

saned disabled; edit /etc/default/saned
 * Restoring resolver state...                  [OK]
 * Starting ACPI daemon                         [OK]
 * Staring regular background processing daemon [OK]
 * Starting CPU interrupts balancing daemon     [OK]
 * Stopping System V runlevel compatibility     [OK]
 * Stopping network connection manager          [OK]
 * Starting SMB/CIFS File and Active Directory Server [OK]

I solved the problem by logging in ( Ctrl+Alt+F2 ) and then upgrading, via sudo apt-get upgrade.

I would assume that some of the files somehow got corrupted previously because of some incomplete update or something similar, and upgrading it properly makes everything work as it should.