ACS: Push Notifications and special characters

The problem

We're currently working on a project where we need to add Push Notifications to our app. Setting it up went fine and the notifications are coming through to the devices on both iOS and Android.

However we have a problem with special characters not being displayed correctly on Android (on iOS it works fine). As we are located in Denmark our clients will need to use special characters like æ, ø, å, Æ, Ø and Å. These are all shown as question marks in the Android Notification when sending form both the ACS Managing tool online and from our own .NET-program which uses the REST API.

We've tried different types of encoding (URL-encoding, UTF8-encoding and unicode-encoding) none of which helps.

Is there a specific way in which the payload must be encoded, for Android to be able to display the special characters?

Example of JSON sent with REST

// URL: https://api.cloud.appcelerator.com/v1/push_notification/notify_tokens.json?key=<our_key_here>
 
{
    "channel": "test",
    "to_tokens": "everyone",
    "payload": {
        "alert": "Push Notification Test øæåÆØÅ"
        "title": "Push Notification Title"
    }
}
 
//Displayed on Android:
//  Push Notification Title
//  Push Notification Test ??????

Environment Information

1. Application type: mobile

2. Titanium SDK: 3.2.2GA

3. Platform and version: Android 4.2.1, Android 4.4.2

4. Device: Samsung Galaxy S2 (with CyanogenMod), Samsung Galaxy S4

5. Titanium Studio: 3.2.1.201402041146