Debian Release 7.3. Reboot issue: /dev/sda1 was not cleanly unmounted check forced.

I have faced with issue in Debian 7.3 release.
On restarting or shutdown - OS was hanging: i had a black screen and nothing was happening after that.
At first time i thought that it could be only once, but it was repeated on each restarting or shutting down.
After PC hanged nothing was possible to do - only turning off and turning on PC - even reset button didn't work.
So, i needed to start PC manually and on next boot i was receiving error message:

/dev/sda1 was not cleanly unmounted check forced.

So, to restart my PC i needed to shutdown with shutdown button, then start, wait when harddisk is checked and then run fsck utility manually to check disk.
It was very boring, so i decided to fix the issue.

At first time i thought, that it could be because of Debian is installed on external USB HDD which is on USB 3.0.
I was trying to use another USB 3.0 port and use USB 2.0, but was no luck.
Then i have checked logs and there also was no errors related with /dev/sda1.
Then i started to search in web and i found that someone also have faced with similar problems, but there was no the solution.
In common i spent about all day to fix the issue, i tried a different things, i wrote on forums - nobody gave me the answer.

Then my best friend give me advice - try to update Debian to newer version.
I have updated Debian from version:
Linux m4p-debian 3.2.0-4-amd64 #1 SMP Debian 3.2.51-1 x86_64 GNU/Linux
to
Linux m4p-debian 3.12.0-031200-generic #201311031935 SMP Mon Nov 4 00:36:54 UTC 2013 x86_64 GNU/Linux

After update - restarting shutdowning is ok and i am really greatful to my friend.
Thank you, Vitya!

Hope this post will be helpful to someone.