hi i have iwl 4965 also iwl 5000 and iwl 5100 dont have 3945 but i found this card work in ubuntu with 2.6.32 and 6.34 and 6.35

first if u have iwl 3945 go to http://intellinuxwireless.org/?n=downloads get your driver put it or install it in your firmwares 

than u also can got to http://wireless.kernel.org/download/compat-wireless-2.6/  get the latest driver those drivers are updated daily. 
download the latest one than make sudo make install 

your internet will work for sure now !!!!


just to show u my does and what driver i do use look

Linux matrix 2.6.35-19-generic #25~lucid1-Ubuntu SMP Wed Aug 25 04:24:28 UTC 2010 i686 GNU/Linux


modinfo iwlagn
filename:       /lib/modules/2.6.35-19-generic/updates/drivers/net/wireless/iwlwifi/iwlagn.ko
alias:          iwl4965
license:        GPL
author:         Copyright(c) 2003-2010 Intel Corporation <email address hidden>
version:        in-tree:
description:    Intel(R) Wireless WiFi Link AGN driver for Linux
firmware:       iwlwifi-4965-2.ucode
firmware:       iwlwifi-5150-2.ucode
firmware:       iwlwifi-5000-2.ucode
firmware:       iwlwifi-6000g2b-5.ucode
firmware:       iwlwifi-6000g2a-5.ucode
firmware:       iwlwifi-6050-4.ucode
firmware:       iwlwifi-6000-4.ucode
firmware:       iwlwifi-1000-3.ucode
srcversion:     8BEA3A15EF75E9324B7D3B9
alias:          pci:v00008086d00000084sv*sd00001316bc*sc*i*
alias:          pci:v00008086d00000084sv*sd00001216bc*sc*i*
alias:          pci:v00008086d00000083sv*sd00001326bc*sc*i*
alias:          pci:v00008086d00000083sv*sd00001226bc*sc*i*
alias:          pci:v00008086d00000083sv*sd00001306bc*sc*i*
alias:          pci:v00008086d00000083sv*sd00001206bc*sc*i*
alias:          pci:v00008086d00000084sv*sd00001315bc*sc*i*
alias:          pci:v00008086d00000084sv*sd00001215bc*sc*i*
alias:          pci:v00008086d00000083sv*sd00001325bc*sc*i*
alias:          pci:v00008086d00000083sv*sd00001225bc*sc*i*
alias:          pci:v00008086d00000083sv*sd00001305bc*sc*i*
alias:          pci:v00008086d00000083sv*sd00001205bc*sc*i*
alias:          pci:v00008086d00000886sv*sd00001316bc*sc*i*
alias:          pci:v00008086d00000886sv*sd00001315bc*sc*i*
alias:          pci:v00008086d00000885sv*sd00001326bc*sc*i*
alias:          pci:v00008086d00000885sv*sd00001325bc*sc*i*
alias:          pci:v00008086d00000885sv*sd00001306bc*sc*i*
alias:          pci:v00008086d00000885sv*sd00001305bc*sc*i*
alias:          pci:v00008086d00000089sv*sd00001316bc*sc*i*
alias:          pci:v00008086d00000089sv*sd00001311bc*sc*i*
alias:          pci:v00008086d00000087sv*sd00001326bc*sc*i*
alias:          pci:v00008086d00000087sv*sd00001321bc*sc*i*
alias:          pci:v00008086d00000087sv*sd00001306bc*sc*i*
alias:          pci:v00008086d00000087sv*sd00001301bc*sc*i*
alias:          pci:v00008086d00000091sv*sd00005226bc*sc*i*
alias:          pci:v00008086d00000091sv*sd00005225bc*sc*i*
alias:          pci:v00008086d00000091sv*sd00005221bc*sc*i*
alias:          pci:v00008086d00000091sv*sd00005207bc*sc*i*
alias:          pci:v00008086d00000091sv*sd00005206bc*sc*i*
alias:          pci:v00008086d00000091sv*sd00005205bc*sc*i*
alias:          pci:v00008086d00000091sv*sd00005201bc*sc*i*
alias:          pci:v00008086d00000090sv*sd00005216bc*sc*i*
alias:          pci:v00008086d00000090sv*sd00005215bc*sc*i*
alias:          pci:v00008086d00000090sv*sd00005211bc*sc*i*
alias:          pci:v00008086d0000008Bsv*sd00005315bc*sc*i*
alias:          pci:v00008086d0000008Bsv*sd00005311bc*sc*i*
alias:          pci:v00008086d0000008Asv*sd00005325bc*sc*i*
alias:          pci:v00008086d0000008Asv*sd00005321bc*sc*i*
alias:          pci:v00008086d0000008Asv*sd00005307bc*sc*i*
alias:          pci:v00008086d0000008Asv*sd00005305bc*sc*i*
alias:          pci:v00008086d0000008Asv*sd00005301bc*sc*i*
alias:          pci:v00008086d0000008Fsv*sd00005207bc*sc*i*
alias:          pci:v00008086d0000008Fsv*sd00005226bc*sc*i*
alias:          pci:v00008086d00000090sv*sd00005216bc*sc*i*
alias:          pci:v00008086d0000008Fsv*sd00005206bc*sc*i*
alias:          pci:v00008086d0000008Fsv*sd00005221bc*sc*i*
alias:          pci:v00008086d00000090sv*sd00005211bc*sc*i*
alias:          pci:v00008086d0000008Fsv*sd00005201bc*sc*i*
alias:          pci:v00008086d0000008Fsv*sd00005107bc*sc*i*
alias:          pci:v00008086d0000008Fsv*sd00005125bc*sc*i*
alias:          pci:v00008086d00000090sv*sd00005115bc*sc*i*
alias:          pci:v00008086d0000008Fsv*sd00005105bc*sc*i*
alias:          pci:v00008086d00000085sv*sd00001316bc*sc*i*
alias:          pci:v00008086d00000085sv*sd00001311bc*sc*i*
alias:          pci:v00008086d00000082sv*sd00001326bc*sc*i*
alias:          pci:v00008086d00000082sv*sd00001321bc*sc*i*
alias:          pci:v00008086d00000082sv*sd00001307bc*sc*i*
alias:          pci:v00008086d00000082sv*sd00001306bc*sc*i*
alias:          pci:v00008086d00000082sv*sd00001301bc*sc*i*
alias:          pci:v00008086d00000082sv*sd00001207bc*sc*i*
alias:          pci:v00008086d00000082sv*sd00001226bc*sc*i*
alias:          pci:v00008086d00000085sv*sd00001216bc*sc*i*
alias:          pci:v00008086d00000082sv*sd00001206bc*sc*i*
alias:          pci:v00008086d00000082sv*sd00001221bc*sc*i*
alias:          pci:v00008086d00000085sv*sd00001211bc*sc*i*
alias:          pci:v00008086d00000082sv*sd00001201bc*sc*i*
alias:          pci:v00008086d00004239sv*sd00001316bc*sc*i*
alias:          pci:v00008086d00004239sv*sd00001311bc*sc*i*
alias:          pci:v00008086d00004238sv*sd00001111bc*sc*i*
alias:          pci:v00008086d0000422Csv*sd00001326bc*sc*i*
alias:          pci:v00008086d0000422Csv*sd00001321bc*sc*i*
alias:          pci:v00008086d0000422Csv*sd00001307bc*sc*i*
alias:          pci:v00008086d0000422Csv*sd00001306bc*sc*i*
alias:          pci:v00008086d0000422Csv*sd00001301bc*sc*i*
alias:          pci:v00008086d0000422Bsv*sd00001121bc*sc*i*
alias:          pci:v00008086d0000422Bsv*sd00001101bc*sc*i*
alias:          pci:v00008086d0000423Dsv*sd00001316bc*sc*i*
alias:          pci:v00008086d0000423Dsv*sd00001216bc*sc*i*
alias:          pci:v00008086d0000423Dsv*sd00001311bc*sc*i*
alias:          pci:v00008086d0000423Dsv*sd00001211bc*sc*i*
alias:          pci:v00008086d0000423Csv*sd00001321bc*sc*i*
alias:          pci:v00008086d0000423Csv*sd00001221bc*sc*i*
alias:          pci:v00008086d0000423Csv*sd00001306bc*sc*i*
alias:          pci:v00008086d0000423Csv*sd00001206bc*sc*i*
alias:          pci:v00008086d0000423Csv*sd00001301bc*sc*i*
alias:          pci:v00008086d0000423Csv*sd00001201bc*sc*i*
alias:          pci:v00008086d0000423Bsv*sd00001011bc*sc*i*
alias:          pci:v00008086d0000423Asv*sd00001021bc*sc*i*
alias:          pci:v00008086d0000423Asv*sd00001001bc*sc*i*
alias:          pci:v00008086d00004236sv*sd00001114bc*sc*i*
alias:          pci:v00008086d00004236sv*sd00001014bc*sc*i*
alias:          pci:v00008086d00004236sv*sd00001111bc*sc*i*
alias:          pci:v00008086d00004236sv*sd00001011bc*sc*i*
alias:          pci:v00008086d00004235sv*sd00001104bc*sc*i*
alias:          pci:v00008086d00004235sv*sd00001004bc*sc*i*
alias:          pci:v00008086d00004235sv*sd00001101bc*sc*i*
alias:          pci:v00008086d00004235sv*sd00001001bc*sc*i*
alias:          pci:v00008086d00004235sv*sd00001124bc*sc*i*
alias:          pci:v00008086d00004235sv*sd00001024bc*sc*i*
alias:          pci:v00008086d00004235sv*sd00001121bc*sc*i*
alias:          pci:v00008086d00004235sv*sd00001021bc*sc*i*
alias:          pci:v00008086d00004237sv*sd00001316bc*sc*i*
alias:          pci:v00008086d00004237sv*sd00001216bc*sc*i*
alias:          pci:v00008086d00004237sv*sd00001315bc*sc*i*
alias:          pci:v00008086d00004237sv*sd00001215bc*sc*i*
alias:          pci:v00008086d00004237sv*sd00001314bc*sc*i*
alias:          pci:v00008086d00004237sv*sd00001214bc*sc*i*
alias:          pci:v00008086d00004237sv*sd00001311bc*sc*i*
alias:          pci:v00008086d00004237sv*sd00001211bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001326bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001226bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001325bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001225bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001324bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001224bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001321bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001221bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001306bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001206bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001305bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001205bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001304bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001204bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001301bc*sc*i*
alias:          pci:v00008086d00004232sv*sd00001201bc*sc*i*
alias:          pci:v00008086d00004230sv*sd*bc*sc*i*
alias:          pci:v00008086d00004229sv*sd*bc*sc*i*
depends:        iwlcore,mac80211,cfg80211
vermagic:       2.6.35-19-generic SMP mod_unload modversions 686 
parm:           swcrypto50:using crypto in software (default 0 [hardware]) (deprecated) (bool)
parm:           swcrypto:using crypto in software (default 0 [hardware]) (int)
parm:           queues_num50:number of hw queues in 50xx series (deprecated) (int)
parm:           queues_num:number of hw queues. (int)
parm:           11n_disable50:disable 50XX 11n functionality (deprecated) (int)
parm:           11n_disable:disable 11n functionality (int)
parm:           amsdu_size_8K50:enable 8K amsdu size in 50XX series (deprecated) (int)
parm:           amsdu_size_8K:enable 8K amsdu size (int)
parm:           fw_restart50:restart firmware in case of error (deprecated) (int)
parm:           fw_restart:restart firmware in case of error (int)
parm:           disable_hw_scan:disable hardware scanning (default 0) (int)
parm:           ucode_alternative:specify ucode alternative to use from ucode file (int)
parm:           antenna_coupling:specify antenna coupling in dB (defualt: 0 dB) (int)
parm:           bt_ch_announce:Enable BT channel announcement mode (default: enable) (bool)