I'm running Xamarin's iOS Build Host app on my machine. It uses telnet on port 5000 to allow connections to it. Suddenly, this connection no longer works.
telnet localhost 5000 HELO
However if I boot my Mavericks into safe mode and do the same, I first get a question if "mtbserver" should allow incoming connections. Afterwards, the telnet connection succeeds.
Back in normal mode, I have already tried to disable the firewall but without success.