Huge Special Characters problem

I have a problem regarding special characters that are appearing messed up on the front-end . mainly the get converted to question marks, or something like ??)

Example – Frédèric becomes Fr?d?ric.

some facts that made me puzzled:

• This WP install is on LOCAL machine, and shares the server with at
  least 40 other installs – none of which have this problem.
• This WP install shares also the same DB as the others .
• My wp-config file has the collate and charset defined.
• The DB seems fine , because when I am viewing the post in the EDITOR (back end) – all is correct , the problem is only on the FRONT end .
• The DB seems fine (2) , opening the post in phpMyAdmin and checking the direct value – all characters are fine .
• This problem is NOT a browser/os encoding , it was checked in 4
  different machines, 3 OS, and 9 browsers..

I have tried all the solutions which I know from past experience, which include :

• checking the wp-config (it is ok, utf-8 defined, collate ok)
• Checking the DB – all UTF-8
• checking my header (<?php bloginfo('charset'); ?>) – that renders correctly as utf-8 with valid markup.
• Open all theme files in my editor, convert encoding to UTF-8 without bom and save.

Did i missed something ? Any Ideas ??