Comment 24 for bug 149214

Yesterday I had found the solution. Ubuntu seems to use old Intel firmware and the issue will be resolved if you perform the following steps:
- Download the last firmware archive from http://www.intellinuxwireless.org/?p=iwlwifi&n=Downloads . The file's name is iwlwifi-4965-ucode-version number.tgz
- Unpack the archive tar xvf iwlwifi-4965-ucode-what version you got.tgz
- Copy iwlwifi-4965.ucode from the unpacked folder into /lib/firmware/your kernel version/iwlwifi-4965.ucode and /lib/firmware/your kernel version/iwlwifi-4965-1.ucode (you should overwrite two files with the same data)

After that you need to reboot or just to say
rmmod iwl4965
modprobe iwl4965
Now on my computer it have been working for the 24 hours continuously without any disconnect. But I can not guarantee it works everywhere.