I've recently installed Ubuntu 12.04 on my old HP laptop in the hopes of extending its usefulness for a little while longer. Unfortunately, I'm having some fairly irritating problems in the wireless department. Specifically, the wireless connection drops out every ten minutes or so (typically only when active, such as during downloads, during system updates, or when watching something on YouTube) before struggling to reconnect and/or deciding to ask me to re-enter network credentials.

To make matters worse, this network cutout affects every other device in my house - my iMac, my parents' computer, the upstairs Blu-Ray player, you name it. I'm sure it's not the ISP or router itself causing the issue, because this is only a problem when I'm running Linux - it has never happened otherwise. This leads me to believe it's an issue with my wireless card or the associated drivers. I spent nearly half of yesterday trying to fix the problem, but have thus far had no success.

Now before I get into other, problem-related details, I should probably list some system specs and show the results I'm getting from related commands. Please bear in mind that, though I have tried to do my research here, I am a relative newb to the whole Linux thing and so do not fully understand all the readouts:

Wireless card: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection (rev02)
Security: WPA/WPA2.
Build: Ubuntu 12.04 LTS.
IPv6: not enabled.

lshw -C network
WARNING: you should run this program as super-user.
description: Ethernet interface
product: NetXtreme BCM5753M Gigabit Ethernet PCI Express
vendor: Broadcom Corporation
physical id: 0
bus info: pci@0000:08:00.0
logical name: eth0
version: 21
serial: 00:1b:38:31:05:ac
capacity: 1Gbit/s
width: 64 bits
clock: 33MHz
capabilities: bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=tg3 driverversion=3.121 firmware=5753m-v3.56 latency=0 multicast=yes port=twisted pair
resources: irq:46 memory:f4100000-f410ffff
description: Wireless interface
product: PRO/Wireless 3945ABG [Golan] Network Connection
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:10:00.0
logical name: wlan0
version: 02
serial: 00:1b:77:65:50:4c
width: 32 bits
clock: 33MHz
capabilities: bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwl3945 driverversion=3.2.0-29-generic-pae firmware= ip= latency=0 multicast=yes wireless=IEEE 802.11abg
resources: irq:44 memory:f4000000-f4000fff
WARNING: output may be incomplete or inaccurate, you should run this program as super-user.

lo no wireless extensions.

wlan0 IEEE 802.11abg ESSID:"@Home"
Mode:Managed Frequency:2.412 GHz Access Point: 00:1E:2A:62:08:24
Bit Rate=54 Mb/s Tx-Power=15 dBm
Retry long limit:7 RTS thrff Fragment thrff
Power Managementff
Link Quality=43/70 Signal level=-67 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:39 Invalid misc:2870 Missed beacon:0

eth0 no wireless extensions.

modinfo iwl3945
filename: /lib/modules/3.2.0-29-generic-pae/kernel/drivers/net/wireless/iwlegacy/iwl3945.ko
firmware: iwlwifi-3945-2.ucode
license: GPL
author: Copyright(c) 2003-2011 Intel Corporation <ilw@linux.intel.com>
version: in-tree:s
description: Intel(R) PRO/Wireless 3945ABG/BG Network Connection driver for Linux
srcversion: 301B04B4010DED41B0830D0
alias: pci:v00008086d00004227sv*sd*bc*sc*i*
alias: pci:v00008086d00004222sv*sd*bc*sc*i*
alias: pci:v00008086d00004227sv*sd00001014bc*sc*i*
alias: pci:v00008086d00004222sv*sd00001044bc*sc*i*
alias: pci:v00008086d00004222sv*sd00001034bc*sc*i*
alias: pci:v00008086d00004222sv*sd00001005bc*sc*i*
depends: iwl-legacy,cfg80211,mac80211
intree: Y
vermagic: 3.2.0-29-generic-pae SMP mod_unload modversions 686
parm: antenna:select antenna (1=Main, 2=Aux, default 0 [both]) (int)
parm: swcrypto:using software crypto (default 1 [software]) (int)
parm: disable_hw_scan:disable hardware scanning (default 1) (int)
parm: fw_restart:restart firmware in case of error (int)

Now, in the threads I've seen, anyone with the same wireless card and similar problems has been referred to one of three solutions. The first, to install a kernel driver, I have unsuccessfully attempted, perhaps because I am unsure of certain commands. The second, to turn off the wireless power settings, is ineffective because (as you can probably see above) said settings are already off. And the third, being related to a completely separate build of Linux, was irrelevant.

Another thing I note is this mention of 'superuser' status under the lshw -C command above, which I do not know how to access (or whether I ought to given my limited knowledge). Now I know that 'root' is the deep-level system access, deeper than the users' credentials or than an Administrator on a Windows machine; I'm guessing that 'superuser' is similar, but less so. What to do with that information, however, I have no idea.

Based on what you see here, what steps would you recommend I take to further diagnose this issue and/or find some sort of solution? I truly appreciate any and all suggestions.