The affected version is svn3578. I'm running an openvpn tunnel over a broadband
ppp connection. When closing the VPN connection, the direct route to the VPN
gateway via the ppp0 device is not removed. It works fine with VPN over
Ethernet, and the problem occurs then the VPN is established over a ppp device.

After playing a bit with the code dealing with libnl, I came to this
modification that works for me, both with point-to-point and ethernet link:

--- NetworkManager-0.7.0.orig/src/NetworkManagerSystem.c        2008-04-15
22:50:36.000000000 +0200
+++ NetworkManager-0.7.0/src/NetworkManagerSystem.c     2008-04-19
17:14:59.000000000 +0200
@@ -190,11 +190,8 @@
        struct rtnl_addr *addr = (struct rtnl_addr *) object;
        int err;
 
-       /* Delete addresses on this interface which don't match the one we
-        * are about to add to it.
-        */
-       if (nl_object_identical ((struct nl_object *) data->match, (struct
nl_object *) addr))
-               return;
+       /* Delete addresses on this interface */
+       
        if (rtnl_addr_get_ifindex (addr) != rtnl_addr_get_ifindex (data->match))
                return;
        if (rtnl_addr_get_family (addr) != rtnl_addr_get_family (data->match))


Moreover, after openvpn initialization completes, I have this WARN in my log :

Apr 19 17:03:14 localhost nm-openvpn[13923]: Initialization Sequence Completed
Apr 19 17:03:14 localhost NetworkManager: <WARN> 
nm_system_vpn_device_set_from_ip4_config(): error -17 returned from
rtnl_addr_add():#012Sucess#012
Apr 19 17:03:15 localhost NetworkManager: <info>  VPN connection 'creatis' (IP
Config Get) complete.
Apr 19 17:03:15 localhost NetworkManager: <info>  VPN plugin state changed: 4

And removing this call to rtnl_addr_add() in the function
nm_system_vpn_device_set_from_ip4_config() also works for me, without loosing
the neeeded routes and the IP configuration of my VPN client.