WordPress has an ugly default feature to turn " or ' into ` and all kind of crazy letters. This is somewhere ok unless you write code as in my case. Then all of your code will be unusable.
Here is a simple solution to disable this smart auto formatting. Open the file wp-includes/default-filters.php and comment the following line:
//add_filter('the_content', 'wptexturize');
I've searched for another more civilized solution but to no avail. Needless to say this works with any theme, any character encoding and makes no other changes to WordPress's default behavior.