This problem started to occur to me while moving to kernel 22.214.171.124
The problem is that the file doesn't exits. I was able to fix it by downloading the latest image (iwlwifi-4965-ucode-126.96.36.199.tgz) from Intel Linux Wireless. Once downloaded and unpacked copy iwlwifi-4965-2.ucode to /lib/firmware/
$ wget http://intellinuxwireless.org/iwlwifi/downloads/iwlwifi-4965-ucode-188.8.131.52.tgz
$ tar xzvf iwlwifi-4965-ucode-184.108.40.206.tgz
$ cp iwlwifi-4965-ucode-220.127.116.11/iwlwifi-4965-2.ucode /lib/firmware/
This was performed on a Lenovo R61 running Debian.