diff --git a/system-config-network-1.5.99-NoneIPLen.patch b/system-config-network-1.5.99-NoneIPLen.patch
new file mode 100644
index 0000000..07813e3
--- /dev/null
+++ b/system-config-network-1.5.99-NoneIPLen.patch
@@ -0,0 +1,16 @@
+diff -up system-config-network-1.5.99/src/netconfpkg/NCDevice.py.NoneIPLen system-config-network-1.5.99/src/netconfpkg/NCDevice.py
+--- system-config-network-1.5.99/src/netconfpkg/NCDevice.py.NoneIPLen	2009-08-12 16:28:33.000000000 +0200
++++ system-config-network-1.5.99/src/netconfpkg/NCDevice.py	2009-12-07 11:05:08.000000000 +0100
+@@ -390,10 +390,10 @@ class Device(Device_base):
+         conf.fsf()
+ 
+         if self.BootProto == None:
+-            if len(self.IP):
++            if self.IP:
+                 self.BootProto = "none"
+             else:
+-                self.BootProto = 'dhcp'                
++                self.BootProto = 'dhcp'
+ 
+         if self.BootProto:
+             self.BootProto = self.BootProto.lower()
diff --git a/system-config-network.spec b/system-config-network.spec
index 9b1cc7c..98be97c 100644
--- a/system-config-network.spec
+++ b/system-config-network.spec
@@ -5,6 +5,8 @@ Version: 1.5.99
 Release: 1%{?dist}
 URL: http://fedoraproject.org/wiki/SystemConfig/network
 Source0: %{name}-%{version}.tar.bz2
+Patch0: system-config-network-1.5.99-NoneIPLen.patch
+
 License: GPLv2+
 Group: Applications/System 
 BuildArch: noarch
@@ -35,6 +37,7 @@ supporting Ethernet, Wireless, TokenRing, ADSL, ISDN and PPP.
 
 %prep
 %setup -q
+%patch0 -p1 -b .NoneIPLen
 
 %build
 %configure
@@ -103,6 +106,9 @@ rm -rf $RPM_BUILD_ROOT
 %{_bindir}/system-config-network-cmd
 
 %changelog
+* Mon Dec 07 2009 Jiri Popelka <jpopelka@redhat.com>  1.5.99-2
+- Fixed s-control-network crash when adding new modem (bz #544412)
+
 * Mon Sep 14 2009 Harald Hoyer <harald@redhat.com> 1.5.99-1
 - version 1.5.99
 - removed all rhpl requirements