diff --git a/configure.ac b/configure.ac
index e7db854..1bdef8c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -831,6 +831,20 @@ if test "$build_x11vnc" = "yes"; then
 	# configure.ac:690: required file `x11vnc/Makefile.in' not found
 	#
 	AC_CONFIG_FILES([x11vnc/Makefile x11vnc/misc/Makefile x11vnc/misc/turbovnc/Makefile])
+
+	if test ! -z "$with_system_libvncserver" -a "x$with_system_libvncserver" != "xno"; then
+		# need to move local tarball rfb headers aside:
+		hdrs="rfb.h rfbclient.h rfbproto.h rfbregion.h rfbint.h"
+		echo "with-system-libvncserver: moving aside headers $hdrs"
+		for hdr in $hdrs
+		do
+			if test -f "rfb/$hdr"; then
+				echo "with-system-libvncserver: moving rfb/$hdr to rfb/$hdr.ORIG"
+				mv rfb/$hdr rfb/$hdr.ORIG
+			fi
+		done
+		echo "with-system-libvncserver: *NOTE* move them back manually to start over."
+	fi
 fi
 
 AC_CONFIG_COMMANDS([chmod-libvncserver-config],[chmod a+x libvncserver-config])
diff --git a/prepare_x11vnc_dist.sh b/prepare_x11vnc_dist.sh
index d72100d..8867d09 100644
--- a/prepare_x11vnc_dist.sh
+++ b/prepare_x11vnc_dist.sh
@@ -15,6 +15,7 @@ sed -e "s/LibVNCServer, [^,)]*\([(,]\)*/x11vnc, $VERSION\1/g" \
     -e "s/AC_PROG_LIBTOOL/AC_PROG_RANLIB/" \
     -e "s/PKG_CHECK/#PKG_CHECK/" \
     -e 's/if test "x$with_gnutls/with_gnutls=no; if test "x$with_gnutls/' \
+    -e 's/if test "x$with_ipv6/with_ipv6=no; if test "x$with_ipv6/' \
 > configure.ac
 
 mv Makefile.am Makefile.am.LibVNCServer
diff --git a/x11vnc/README b/x11vnc/README
index 310ec36..42cab34 100644
--- a/x11vnc/README
+++ b/x11vnc/README
@@ -2,7 +2,7 @@
 Copyright (C) 2002-2010 Karl J. Runge <runge@karlrunge.com>
 All rights reserved.
 
-x11vnc README file                         Date: Tue Dec 21 11:45:35 EST 2010
+x11vnc README file                         Date: Tue Dec 21 13:47:44 EST 2010
 
 The following information is taken from these URLs:
 
@@ -12285,7 +12285,7 @@ x11vnc: a VNC server for real X displays
    Here are all of x11vnc command line options:
 % x11vnc -opts      (see below for -help long descriptions)
 
-x11vnc: allow VNC connections to real X11 displays. 0.9.13 lastmod: 2010-12-20
+x11vnc: allow VNC connections to real X11 displays. 0.9.13 lastmod: 2010-12-21
 
 x11vnc options:
   -display disp            -auth file               -N                     
@@ -12416,7 +12416,7 @@ libvncserver-tight-extension options:
 
 % x11vnc -help
 
-x11vnc: allow VNC connections to real X11 displays. 0.9.13 lastmod: 2010-12-20
+x11vnc: allow VNC connections to real X11 displays. 0.9.13 lastmod: 2010-12-21
 
 (type "x11vnc -opts" to just list the options.)
 
diff --git a/x11vnc/x11vnc.1 b/x11vnc/x11vnc.1
index 8a92433..08a2cd8 100644
--- a/x11vnc/x11vnc.1
+++ b/x11vnc/x11vnc.1
@@ -2,7 +2,7 @@
 .TH X11VNC "1" "December 2010" "x11vnc " "User Commands"
 .SH NAME
 x11vnc - allow VNC connections to real X11 displays
-         version: 0.9.13, lastmod: 2010-12-20
+         version: 0.9.13, lastmod: 2010-12-21
 .SH SYNOPSIS
 .B x11vnc
 [OPTION]...
diff --git a/x11vnc/x11vnc_defs.c b/x11vnc/x11vnc_defs.c
index ae048ee..06318d5 100644
--- a/x11vnc/x11vnc_defs.c
+++ b/x11vnc/x11vnc_defs.c
@@ -47,7 +47,7 @@ int xtrap_base_event_type = 0;
 int xdamage_base_event_type = 0;
 
 /*               date +'lastmod: %Y-%m-%d' */
-char lastmod[] = "0.9.13 lastmod: 2010-12-20";
+char lastmod[] = "0.9.13 lastmod: 2010-12-21";
 
 /* X display info */