Comment 28 for bug 548992

Further to my comment above, this is the content from end of /var/log/daemon.log. It appears to be timing out on a DHCP request. Since my AP hasn't changed in years, it must be a change at the Ubuntu end that has produced this issue. Since the last update, my workaround no longer works around, so am a bit stuck. I tried the disabling IPV6 on the command line but this hasn't helped.

Jun 15 20:33:27 james-desktop NetworkManager: <info> DHCP: device wlan0 state changed normal exit -> preinit
Jun 15 20:33:27 james-desktop dhclient: Listening on LPF/wlan0/00:21:27:c1:33:19
Jun 15 20:33:27 james-desktop dhclient: Sending on LPF/wlan0/00:21:27:c1:33:19
Jun 15 20:33:27 james-desktop dhclient: Sending on Socket/fallback
Jun 15 20:33:31 james-desktop dhclient: DHCPREQUEST of 192.168.1.3 on wlan0 to 255.255.255.255 port 67
Jun 15 20:33:53 james-desktop dhclient: last message repeated 2 times
Jun 15 20:33:53 james-desktop dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 5
Jun 15 20:33:58 james-desktop dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 7
Jun 15 20:34:05 james-desktop dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 14
Jun 15 20:34:13 james-desktop NetworkManager: <info> (wlan0): DHCP transaction took too long, stopping it.
Jun 15 20:34:13 james-desktop NetworkManager: <info> (wlan0): canceled DHCP transaction, dhcp client pid 2175
Jun 15 20:34:13 james-desktop NetworkManager: <info> Activation (wlan0) Stage 4 of 5 (IP4 Configure Timeout) scheduled...
Jun 15 20:34:13 james-desktop NetworkManager: <info> Activation (wlan0) Stage 4 of 5 (IP4 Configure Timeout) started...
Jun 15 20:34:13 james-desktop NetworkManager: <info> (wlan0): device state change: 7 -> 9 (reason 5)
Jun 15 20:34:13 james-desktop NetworkManager: <info> Activation (wlan0) failed for access point (JamesOne)
Jun 15 20:34:13 james-desktop NetworkManager: <info> Marking connection 'JamesOne' invalid.
Jun 15 20:34:13 james-desktop NetworkManager: <info> Activation (wlan0) failed.
Jun 15 20:34:13 james-desktop NetworkManager: <info> Activation (wlan0) Stage 4 of 5 (IP4 Configure Timeout) complete.
Jun 15 20:34:13 james-desktop NetworkManager: <info> (wlan0): device state change: 9 -> 3 (reason 0)
Jun 15 20:34:13 james-desktop NetworkManager: <info> (wlan0): deactivating device (reason: 0).
Jun 15 20:34:13 james-desktop wpa_supplicant[1125]: CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys