Using the translator service with arabic characters

Hi!

When I issue the following request:

http://api.microsofttranslator.com/v2/Http.svc/Translate?appId=0BF0FE2A3F5E7E7D41743E485F9E26E541D0EC5D&text=الترسانة&from=ar&to=en

I get the following response

 <string xmlns="http://schemas.microsoft.com/2003/10/Serialization/">????????</string>

Furthermore when I try to use the "detect" operation I get an "en" answer. Could it be that I need to issue a WebHttpRequest ensuring that the encoding is unicode in order for this to work or is there an issue with arabic characters when using the translator service?

Thanks in advance!