What has changed in the WWW class? What am I doing wrong?

I am switching up to Unity 4.6 from 4.3 (mainly to make use of the new UI). The game needs to get some JSON strings quite regularly from a server. But somehow the good old WWW class seems to be messing up.

All i get from WWW.text is: �

At first i thought it might be a encoding issue and tried a bunch of different System.Text.Encoding stuff without any success (yeah, I tried everything, even though I am sure that the server provides the JSONs in UTF8).

So to investigate further i decided to start a new project solely to test what is going on.

To keep it simple I try to fetch a UTF-8 text file containing "Hello World!"

 void Start () {
         string request = "http://wheremytestfile.is/test.txt";
         WWW www = new WWW (request);
         StartCoroutine (WaitForRequest (www));
     }
 
     IEnumerator WaitForRequest(WWW www){
         yield return www;
 
         if (www.error == null) {
             string wwwBytes = "";
             foreach (var b in www.bytes)
                 wwwBytes +=(b+" ");
             Debug.Log(wwwBytes);
             Debug.Log(www.text.Length);
             Debug.Log(www.text);        
         }
         else{
             Debug.Log(www.error);
         }
     
     }

what happens ist this:

Unity 4.3:

WWW.bytes: 239 187 191 72 101 108 108 111 32 87 111 114 108 100 33

WWW.text.Length: 13

WWW.text: Hello World!

Unity 4.6:

WWW.bytes: 31 139 8 0 0 0 0 0 0 3 123 191 123 191 71 106 78 78 190 66 120 126 81 78 138 34 0 88 34 224 15 15 0 0 0

WWW.text.Length: 35

WWW.text: �

I can even see, that the 71 106 78 78 190 66 120 126 81 78 138 34 part in the 4.6 results should be the Hello World! I am looking for, but quite obviously it's unreadable.

I have absolutely no clue what is going on and feel more noobish than I think I should.

Thank you for your help!