DNS from wifi not removed when switching to wire after suspend/resume

[Frederik Himpe <fhimpe telenet be>]

I'm using NetworkManager 0.7.996 (git 20091021 snapshot) on Mandriva, 
built with dhclient and resolvconf support.

I have a wireless connection to my AP at home and a wired DHCP connection 
configured in networkmanager, both set to autoconnect and available to 
all users. At home, networkmanager connects to my wireless AP 
automatically. Then I suspend my system and resume it at work, where 
it's docked and has a wired DHCP connection. NetworkManager connects 
automatically to the wired connection, and deactivates the wlan0 connection,
however NetworkManager just adds the DNS servers from my wired connection
at work to resolv.conf without removing the DNS server from my wireless
home connection. This results in long waits when resolving hostnames.

Here's a log file of what happens when resuming the system at work:

NNov 17 08:56:24 defected NetworkManager: <info>  Waking up...
Nov 17 08:56:24 defected NetworkManager: <info>  (eth0): now managed
Nov 17 08:56:24 defected NetworkManager: <info>  (eth0): device state change: 1 -> 2 (reason 2)
Nov 17 08:56:24 defected NetworkManager: <info>  (eth0): preparing device.
Nov 17 08:56:24 defected NetworkManager: <info>  (eth0): deactivating device (reason: 2).
Nov 17 08:56:24 defected NetworkManager: <info>  (wlan0): now managed
Nov 17 08:56:24 defected NetworkManager: <info>  (wlan0): device state change: 1 -> 2 (reason 2)
Nov 17 08:56:24 defected NetworkManager: <info>  (wlan0): bringing up device.
Nov 17 08:56:24 defected kernel: Registered led device: iwl-phy0::radio
Nov 17 08:56:24 defected kernel: Registered led device: iwl-phy0::assoc
Nov 17 08:56:24 defected kernel: Registered led device: iwl-phy0::RX
Nov 17 08:56:24 defected kernel: Registered led device: iwl-phy0::TX
Nov 17 08:56:24 defected NetworkManager: <info>  (wlan0): preparing device.
Nov 17 08:56:24 defected kernel: ADDRCONF(NETDEV_UP): wlan0: link is not ready
Nov 17 08:56:24 defected NetworkManager: <info>  (wlan0): deactivating device (reason: 2).
Nov 17 08:56:24 defected NetworkManager: <info>  (eth0): device state change: 2 -> 3 (reason 0)
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) starting connection 'DHCP connection'
Nov 17 08:56:24 defected NetworkManager: <info>  (eth0): device state change: 3 -> 4 (reason 0)
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 1 of 5 (Device Prepare) scheduled...
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 1 of 5 (Device Prepare) started...
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 2 of 5 (Device Configure) scheduled...
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 1 of 5 (Device Prepare) complete.
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 2 of 5 (Device Configure) starting...
Nov 17 08:56:24 defected NetworkManager: <info>  (eth0): device state change: 4 -> 5 (reason 0)
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 2 of 5 (Device Configure) successful.
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 3 of 5 (IP Configure Start) scheduled.
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 2 of 5 (Device Configure) complete.
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 3 of 5 (IP Configure Start) started...
Nov 17 08:56:24 defected NetworkManager: <info>  (eth0): device state change: 5 -> 7 (reason 0)
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Beginning DHCP transaction (timeout in 45 seconds)
Nov 17 08:56:24 defected dhclient: Internet Systems Consortium DHCP Client 4.1.0p1
Nov 17 08:56:24 defected dhclient: Copyright 2004-2009 Internet Systems Consortium.
Nov 17 08:56:24 defected dhclient: All rights reserved.
Nov 17 08:56:24 defected dhclient: For info, please visit http://www.isc.org/sw/dhcp/
Nov 17 08:56:24 defected dhclient: 
Nov 17 08:56:24 defected NetworkManager: <info>  dhclient started with pid 19111
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 4 of 5 (IP6 Configure Get) scheduled...
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 3 of 5 (IP Configure Start) complete.
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 4 of 5 (IP6 Configure Get) started...
Nov 17 08:56:24 defected NetworkManager: <info>  Activation (eth0) Stage 4 of 5 (IP6 Configure Get) complete.
Nov 17 08:56:24 defected NetworkManager: <info>  (wlan0): supplicant interface state:  starting -> ready
Nov 17 08:56:24 defected NetworkManager: <info>  (wlan0): device state change: 2 -> 3 (reason 42)
Nov 17 08:56:24 defected NetworkManager: <info>  DHCP: device eth0 state changed (null) -> preinit
Nov 17 08:56:24 defected dhclient: Listening on LPF/eth0/00:21:70:ac:b0:8a
Nov 17 08:56:24 defected dhclient: Sending on   LPF/eth0/00:21:70:ac:b0:8a
Nov 17 08:56:24 defected dhclient: Sending on   Socket/fallback
Nov 17 08:56:25 defected kernel: lo: Disabled Privacy Extensions
Nov 17 08:56:26 defected dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3
Nov 17 08:56:26 defected dhclient: DHCPOFFER from 134.184.26.2
Nov 17 08:56:26 defected dhclient: DHCPREQUEST on eth0 to 255.255.255.255 port 67
Nov 17 08:56:26 defected dhclient: DHCPACK from 134.184.26.2
Nov 17 08:56:26 defected NetworkManager: <info>  DHCP: device eth0 state changed preinit -> bound
Nov 17 08:56:26 defected NetworkManager: <info>  Activation (eth0) Stage 4 of 5 (IP4 Configure Get) scheduled...
Nov 17 08:56:26 defected NetworkManager: <info>  Activation (eth0) Stage 4 of 5 (IP4 Configure Get) started...
Nov 17 08:56:26 defected NetworkManager: <info>    address 134.184.26.59
Nov 17 08:56:26 defected NetworkManager: <info>    prefix 24 (255.255.255.0)
Nov 17 08:56:26 defected NetworkManager: <info>    gateway 134.184.26.100
Nov 17 08:56:26 defected NetworkManager: <info>    nameserver '134.184.26.51'
Nov 17 08:56:26 defected NetworkManager: <info>    nameserver '134.184.250.7'
Nov 17 08:56:26 defected NetworkManager: <info>    nameserver '134.184.15.13'
Nov 17 08:56:26 defected NetworkManager: <info>    domain name 'vub.ac.be'
Nov 17 08:56:26 defected NetworkManager: <info>  Activation (eth0) Stage 5 of 5 (IP Configure Commit) scheduled...
Nov 17 08:56:26 defected NetworkManager: <info>  Activation (eth0) Stage 4 of 5 (IP4 Configure Get) complete.
Nov 17 08:56:26 defected NetworkManager: <info>  Activation (eth0) Stage 5 of 5 (IP Configure Commit) started...
Nov 17 08:56:26 defected dhclient: bound to 134.184.26.59 -- renewal in 1801 seconds.
Nov 17 08:56:27 defected NetworkManager: <info>  (eth0): writing resolv.conf to /sbin/resolvconf
Nov 17 08:56:27 defected postfix/postfix-script[19512]: refreshing the Postfix mail system
Nov 17 08:56:27 defected postfix/master[2795]: reload -- version 2.6.5, configuration /etc/postfix
Nov 17 08:56:27 defected NetworkManager: <info>  (eth0): device state change: 7 -> 8 (reason 0)
Nov 17 08:56:27 defected NetworkManager: <info>  (eth0): writing resolv.conf to /sbin/resolvconf
Nov 17 08:56:27 defected NetworkManager: <info>  Policy set 'DHCP connection' (eth0) as default for routing and DNS.
Nov 17 08:56:27 defected NetworkManager: <info>  Activation (eth0) successful, device activated.
Nov 17 08:56:27 defected NetworkManager: <info>  Activation (eth0) Stage 5 of 5 (IP Configure Commit) complete.

Any idea why it does not remove the DNS from my wireless home connection? 

-- 
Frederik Himpe