Convert slash-quotes in file contents

I have a file containing XHTML and PHP coding.
I open the file using a user-interface (HTML-form with textarea) that shows the file’s content in XHTML/PHP coding. With all the HTML tags and PHP scripts intact.

But after editing the file and saving it. All the quotes (single and double) show up as ” or ‘ (escape-chars).

Example:
Opening file for the first time the content shows:
[FONT=”Fixedsys”]<?php echo ‘Show me the money!’; ?>[/FONT]

Opening file for second time the content changed to:
[FONT=”Fixedsys”]<?php echo ‘Show me the money!’; ?>[/FONT]

It’s not suppose to covert quotes to escape-chars.

I’ve tried using htmlspecialchars_decode with flags for quotes and even html_entity_decode with flags. But whatever options I try, every quote is converted to a –quote after saving the file.

How can I solve this?

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