Textarea add rare symbols

I have problems with my textarea. When someone copy text from an html or .txt and paste it in my textarea, the post have rare symbols like: =20, =space, =3D... Anyone have some idea about my problem?? And how could I fix it? My textarea is:

<textarea id="id_message" cols="40" name="message" rows="10"></textarea>

I use Markdown, but I have t开发者_开发问答ried this without javascript and the problem is the same.

I use Django in Google app engine.

Thank you in advance.