UTF8 troubles, multiple sources, storage in MySQL

[devels]

I always have troubles with UTF8.

The scenario: Mulitple sources (like xml, csv, own cms), and one database: Mysql. Information needs to be displayed on a website.

The encoding for xml: encoding="utf-8". So I have words(in dutch) from the xml like: "première", and "één".
Do I need to store these like they are? Special settings needed (collocation?) in the mysql database?
To display these on a webpage I use a utf-8 header using php or a meta tag saying it is utf8.

But the problem then is, while I have words (from other sources) that are already encoded to something like: "één" are not displaying correctly. The webpage then shows: "??n".

What is the best consistent way to avoid these problems?

[nemonoman]

The data may be stored correctly. The problem is with the browsers's handling of the data. I have been particularly frustrated by Safari in this regard.

Safari (it appears) often handles data based on its own internal settings, despite the use of header or Meta tags to reset. Safari users need to change their character set explicitly through their preferences.

Safari is surprisingly non-standards compliant. Firefox and IE are much more compliant to this concern