"umlauts" and Codeigniter...?

[eluser]Unknown[/eluser]
Hello there,

since I am kind of new to the Codeigniter Framework or frameworks at all I'm simply amazed of all its features and power.

But now I got my first Issue.

I'm about to build a comment system for my blog and everything worked well for now...

BUT: If I type in my form some umlauts (e.g. äöüß etc.) the Input gets ignored.

My setup seems to be ok. Each file is in UTF-8, Codeigniter's config files are set to UTF-8 and also the headers are correctly sent.
The reason I think it has something to do with Codeigniter is, that the POST request is correctly sent in a non-Codeigniter Environment with the same form...
And the really strange thing is, that this only appears if I'm running PHP 5.3.5. PHP 5.2.17 does its job well...
("default_charset" is set to "UTF-8" in the php.ini...)

So I'm kind of confused, what happens here...

My form code is:

Code:

<?php
        // only for debugging.
if(isset($_POST)) {
  echo '<pre>';
  print_r($_POST);
  echo '</pre>';
}
?&gt;

&lt;form method="post" action="" accept-charset="utf-8"&gt;

     <label for="username">Name:</label>
     &lt;input type="text" name="username" class="span6"&gt;

     <label for="email">Email:</label>
     &lt;input type="text" name="email" class="span6"&gt;

     <label for="comment">What do you want to say?</label>
     &lt;textarea name="comment" class="span10" rows="8"&gt;&lt;/textarea>
    
     &lt;input type="submit" value="Submit Comment" class="btn primary" id="submit" name="submit"&gt;
     &lt;input type="reset" value="Reset" class="btn "&gt;
&lt;/form&gt;

If I type an "ü" in every input for instance, the Post-Array looks like this:

Code:

Array
(
    [username] =>
    [email] =>  
    [comment] =>
    [submit] => Submit Comment
)

I'm running my local server with MAMP Pro on Mac OS X Lion and Codeigniter 2.0.3.