OpenVPN configuration assigns duplicate addresses

Binary package hint: network-manager

When connecting to an OpenVPN VPN with NetworkManager, two duplicate IP addresses with only different netmasks are assigned to the tunnel interface. Output of ip addr show dev tun0 is as follows:

4: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1412 qdisc pfifo_fast qlen 100
    link/[65534]
    inet 192.168.11.26 peer 192.168.11.25/32 scope global tun0
    inet 192.168.11.26 peer 192.168.11.25/24 scope global tun0

This breaks some packages such as sofia-sip when they try to glob bind to all addresses on the system which results in "Address already in use" errors.

[02:08:03] [Shuttle] [cobi] [~/sofsipcli/sofsip-cli] $ lsb_release -rd
Description: Ubuntu 8.04.1
Release: 8.04

[02:10:22] [Shuttle] [cobi] [~/sofsipcli/sofsip-cli] $ apt-cache policy network-manager
network-manager:
  Installed: 0.6.6-0ubuntu5
  Candidate: 0.6.6-0ubuntu5
  Version table:
 *** 0.6.6-0ubuntu5 0
        500 http://us.archive.ubuntu.com hardy/main Packages
        100 /var/lib/dpkg/status