UTF-8 characters in the head

twentyeleven child theme
website : http://www.vihegay.com

I get crazy by an old problem which comes back time to time concerning the php files and nobody can tell me a precise answer since years…
If you look at the code source of the page, in the meta description et keywords, the special characters (French é, à, etc.) are transformed to � (question mark in a black square).

1. i have declared :

<meta charset="<?php bloginfo( 'charset' ); ?>" />
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

2. I re-wrote the special characters to ASCII (&ecute; etc.) but when i checked out in the browser, it did not translate them to the right characters but remained the same…

3. i have red somewhere that Dreamweaver can causes problem too, so i copied the codes of the page to a note-pad, saved in UTF-8, and sent to server… without any result. Once note-pad helped me but it does not help anymore…

4. i added special characters to php file (i do not remember what exactly) but did not help…

Please help me, it makes me nervous, i am sure that the answer can not be so special, there are millions who use those characters and who use php system as well… (but i red also that there are many people who have the same problem).