Similar to bug #672449, I found the newer libvncserver0 would listen on ipv6 port 5900 if no -rfbportv6 parameter is passed to it. Passing "-rfbportv6 -1" seems to work:
x11vnc -no6 -shared -many -localhost -rfbport 5901 -rfbportv6 -1
08/02/2013 12:21:52 Listening for VNC connections on TCP port 5901
08/02/2013 12:21:52 rfbListenOnTCP6Port error in getaddrinfo: Servname not
supported for ai_socktype
