When any VPN is connecting/connected/disconnecting,Tunnelblick uses a localhost port to connect to OpenVPN's management interface. It searches for an open port starting with port 1024 and uses that port.
It is very common for the first open port to be 1337, which is also a miceandmen port.
You can specify the port at which the search starts with the following Terminal command:
defaults write net.tunnelblick.tunnelblick managementPortStartingPortNumber -int NNN
where NNN is the port number (from 1024 to 65535.