QTcpServer listen error

I've build Qt5 alfa from git using mingw(4.6.1), active perl 5.14.2 and active python 2.7.2. Now i've tested the network examples and all of fortuneserver, threadedfortuneserver or loopback fails in QTcpServer::listen. Trying under debug mode their fails at d->socketEngine->bind(addr, port) in qtcpserver.cpp line 310.