После загрузки Wi-Fi не будет работать, пока не отключен и не включен повторно

Question 1

После загрузки Ubuntu 12.04 64 bit я не могу подключиться к Wi-Fi, пока я не отключусь и не подключусь снова. Это происходило некоторое время, но я, наконец, устала от повторного подключения после загрузки, поэтому я пытаюсь это исправить. В моих усилиях по устранению неполадок здесь есть то, что я имею до сих пор:

Когда Wi-Fi не работает, я не могу пропинговать адреса локальной сети
Я получаю то же поведение, что и вошедший в систему как другой пользователь
Изменение настроек IPv6 на «игнорировать» не имеет никакого эффекта, несмотря на IPv6 Configure Timeout (см. журнал ниже).

Вот что я получаю из grep Network /var/log/syslog, когда Wi-Fi не работает:

NetworkManager[1132]: <info> (wlan0): using nl80211 for WiFi device control
NetworkManager[1132]: <info> (wlan0): new 802.11 WiFi device (driver: 'iwlwifi' ifindex: 3)
NetworkManager[1132]: <info> (wlan0): exported as /org/freedesktop/NetworkManager/Devices/1
NetworkManager[1132]: <info> (wlan0): now managed
NetworkManager[1132]: <info> (wlan0): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2]
NetworkManager[1132]: <info> (wlan0): bringing up device.
NetworkManager[1132]: <info> (wlan0): preparing device.
NetworkManager[1132]: <info> (wlan0): deactivating device (reason 'managed') [2]
NetworkManager[1132]: <warn> /sys/devices/virtual/net/lxcbr0: couldn't determine device driver; ignoring...
NetworkManager[1132]: <info> wpa_supplicant started
NetworkManager[1132]:        SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/lxcbr0, iface: lxcbr0)
NetworkManager[1132]:        SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/lxcbr0, iface: lxcbr0): no ifupdown configuration found.
NetworkManager[1132]: <warn> /sys/devices/virtual/net/lxcbr0: couldn't determine device driver; ignoring...
NetworkManager[1132]: <info> (wlan0): supplicant interface state: starting -> ready
NetworkManager[1132]: <info> (wlan0): device state change: unavailable -> disconnected (reason 'supplicant-available') [20 30 42]
NetworkManager[1132]: <info> (wlan0): supplicant interface state: ready -> inactive
NetworkManager[1132]: <warn> Trying to remove a non-existant call id.
NetworkManager[1132]:        SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/virbr0, iface: virbr0)
NetworkManager[1132]:        SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/virbr0, iface: virbr0): no ifupdown configuration found.
NetworkManager[1132]: <warn> /sys/devices/virtual/net/virbr0: couldn't determine device driver; ignoring...
NetworkManager[1132]: <info> Auto-activating connection 'Skylab'.
NetworkManager[1132]: <info> Activation (wlan0) starting connection 'Skylab'
NetworkManager[1132]: <info> (wlan0): device state change: disconnected -> prepare (reason 'none') [30 40 0]
NetworkManager[1132]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) scheduled...
NetworkManager[1132]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) started...
NetworkManager[1132]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) scheduled...
NetworkManager[1132]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) complete.
NetworkManager[1132]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) starting...
NetworkManager[1132]: <info> (wlan0): device state change: prepare -> config (reason 'none') [40 50 0]
NetworkManager[1132]: <info> Activation (wlan0/wireless): connection 'Skylab' has security, and secrets exist.  No new secrets needed.
NetworkManager[1132]: <info> Config: added 'ssid' value 'Skylab'
NetworkManager[1132]: <info> Config: added 'scan_ssid' value '1'
NetworkManager[1132]: <info> Config: added 'key_mgmt' value 'WPA-PSK'
NetworkManager[1132]: <info> Config: added 'psk' value '<omitted>'
NetworkManager[1132]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete.
NetworkManager[1132]: <info> Config: set interface ap_scan to 1
NetworkManager[1132]: <info> (wlan0): supplicant interface state: inactive -> scanning
NetworkManager[1132]: <info> (wlan0): supplicant interface state: scanning -> associating
NetworkManager[1132]: <info> (wlan0): supplicant interface state: associating -> associated
NetworkManager[1132]: <info> (wlan0): supplicant interface state: associated -> 4-way handshake
NetworkManager[1132]: <info> (wlan0): supplicant interface state: 4-way handshake -> completed
NetworkManager[1132]: <info> Activation (wlan0/wireless) Stage 2 of 5 (Device Configure) successful.  Connected to wireless network 'Skylab'.
NetworkManager[1132]: <info> Activation (wlan0) Stage 3 of 5 (IP Configure Start) scheduled.
NetworkManager[1132]: <info> Activation (wlan0) Stage 3 of 5 (IP Configure Start) started...
NetworkManager[1132]: <info> (wlan0): device state change: config -> ip-config (reason 'none') [50 70 0]
NetworkManager[1132]: <info> Activation (wlan0) Beginning DHCPv4 transaction (timeout in 45 seconds)
NetworkManager[1132]: <info> dhclient started with pid 2157
NetworkManager[1132]: <info> Activation (wlan0) Beginning IP6 addrconf.
NetworkManager[1132]: <info> Activation (wlan0) Stage 3 of 5 (IP Configure Start) complete.
NetworkManager[1132]: <info> (wlan0): DHCPv4 state changed nbi -> preinit
NetworkManager[1132]: <info> (wlan0): DHCPv4 state changed preinit -> reboot
NetworkManager[1132]: <info>   address 192.168.2.9
NetworkManager[1132]: <info>   prefix 24 (255.255.255.0)
NetworkManager[1132]: <info>   gateway 192.168.2.1
NetworkManager[1132]: <info>   nameserver '192.168.2.1'
NetworkManager[1132]: <info>   domain name 'Belkin'
NetworkManager[1132]: <info> Activation (wlan0) Stage 5 of 5 (IPv4 Configure Commit) scheduled...
NetworkManager[1132]: <info> Activation (wlan0) Stage 5 of 5 (IPv4 Commit) started...
NetworkManager[1132]: <info> DNS: starting dnsmasq...
NetworkManager[1132]: <info> (wlan0): writing resolv.conf to /sbin/resolvconf
NetworkManager[1132]: <info> (wlan0): device state change: ip-config -> activated (reason 'none') [70 100 0]
NetworkManager[1132]: <info> Policy set 'Skylab' (wlan0) as default for IPv4 routing and DNS.
NetworkManager[1132]: <info> Activation (wlan0) successful, device activated.
NetworkManager[1132]: <info> Activation (wlan0) Stage 5 of 5 (IPv4 Commit) complete.
NetworkManager[1132]: <info> (wlan0): IP6 addrconf timed out or failed.
NetworkManager[1132]: <info> Activation (wlan0) Stage 4 of 5 (IPv6 Configure Timeout) scheduled...
NetworkManager[1132]: <info> Activation (wlan0) Stage 4 of 5 (IPv6 Configure Timeout) started...
NetworkManager[1132]: <info> Activation (wlan0) Stage 4 of 5 (IPv6 Configure Timeout) complete.

Остальное присутствует только когда Wifi не работает:

NetworkManager[1132]: <info> Activation (wlan0) Stage 5 of 5 (IPv4 Configure Commit) scheduled...
NetworkManager[1132]: <info> Activation (wlan0) Stage 5 of 5 (IPv4 Commit) started...
NetworkManager[1132]: <info> DNS: starting dnsmasq...
NetworkManager[1132]: <info> (wlan0): writing resolv.conf to /sbin/resolvconf
NetworkManager[1132]: <info> (wlan0): device state change: ip-config -> activated (reason 'none') [70 100 0]
NetworkManager[1132]: <info> Policy set 'Skylab' (wlan0) as default for IPv4 routing and DNS.
NetworkManager[1132]: <info> Activation (wlan0) successful, device activated.
NetworkManager[1132]: <info> Activation (wlan0) Stage 5 of 5 (IPv4 Commit) complete.

Вот информация о моей беспроводной карте из lspci -v:

08:00.0 Network controller: Intel Corporation Centrino Wireless-N 1000
Subsystem: Intel Corporation Centrino Wireless-N 1000 BGN
Flags: bus master, fast devsel, latency 0, IRQ 44
Memory at d1d00000 (64-bit, non-prefetchable) [size=8K]
Capabilities: [c8] Power Management version 3
Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [e0] Express Endpoint, MSI 00
Capabilities: [100] Advanced Error Reporting
Capabilities: [140] Device Serial Number 74-e5-0b-ff-ff-7d-3a-38
Kernel driver in use: iwlwifi
Kernel modules: iwlwifi

Не уверен, куда идти с этим, любая помощь приветствуется, включая советы по устранению неполадок. Заранее спасибо.

Question 2