subject says it all, x11vnc crashes when hosts disable ipv6 support (kernel booted with ipv6.disable=1 option), see also downstream reports:
https://bugzilla.redhat.com/show_bug.cgi?id=972618
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=735648
https://bugs.launchpad.net/ubuntu/+source/x11vnc/+bug/1175098
https://bugs.launchpad.net/ubuntu/+source/x11vnc/+bug/1070614
downstream reports include several backtraces, but I don't think any include one with full debuginfo (yet).
Please note that LibVNCServer's ticket system on SourceForge should be disabled (but I don't know how) because it is not actively monitored.
So please move the discussion to the mailing list.
(As preliminary feedback, which I will gladly clarify on the mailing list, the use case illustrated at least in the first downstream link is only supported by disabling IPv6 support at compile time for now.)