Multicast receiver example fails when executed twice on same machine

So basically i've got the problem that i can't bind two QUdpSockets (used for multicast) on the same address/port, even though i am using QAbstractSocket::ShareAddress.

Code:

---

udpSocket4.bind(QHostAddress::AnyIPv4, 45454, QUdpSocket::ShareAddress)

---

I always get the error "The bound address is already in use". After i searched for a while to find my problem, i created a new project and ran the offical multicast receiver example twice on my machine. It also fails to bind the socket the second time. Even if i use two different ports (in my code) the binding fails because QHostAddress::AnyIPv4 stays the same. So my questions are: is this behavior intended and i just misunderstand the ShareAddress flag? And if so, is there a way with Qt to set the socket option SO_REUSEADDR to bind two sockets on the same address?
I am using a windows 8.1 machine and i am aware of the fact that ShareAddress is disabled on windows. But i looked into the source code and as far as i understand it, windows will only block reusing the same address if someone declares DontShareAddress.

Thanks for the help and sorry for my english, not a native speaker :)