When you backup your database, it is not always saved with UTF-8 collation. This is a problem if you have some special characters because after a database restore they won't be displayed properly unless the database is with UTF-8 collation.

The easiest solution is, once you dump the database, to open the sql file with Notepad, click on File > Save As and choose UTF-8 next to Encoding. Save the new file. Now you will have a dump of your database with UTF-8 collation :)