Well, the solution is quite simple: the messages are not transmitted as /TextMessage/ objects in the sense of activemq-cpp, they are /ByteMessage/'s.
Casting the message to a ByteMessage, read the bytes and creating a string from it solved it. Unfortunately neither the readString() nor the readUTF() method are working for some reason... but anyway, as long as I get the bytes I am fine. -- Sent from: http://activemq.2283324.n4.nabble.com/ActiveMQ-User-f2341805.html