Comment 7 for bug 794291

Similar problem for me. After updating to the 2.6.32-33-generic-pae kernel my intel wireless stopped working. dmesg shows:
[ 15.261265] iwlagn 0000:03:00.0: firmware: requesting iwlwifi-5000-5.ucode
[ 15.454997] iwlagn 0000:03:00.0: Driver unable to support your firmware API. Driver supports v5, firmware is v0.
[ 15.455008] iwlagn 0000:03:00.0: Could not read microcode: -22
[ 15.951086] iwlagn 0000:03:00.0: firmware: requesting iwlwifi-5000-5.ucode
[ 15.953192] iwlagn 0000:03:00.0: Driver unable to support your firmware API. Driver supports v5, firmware is v0.
[ 15.953208] iwlagn 0000:03:00.0: Could not read microcode: -22

I tried this with both 1.34.7 and 1.34.10 of linux-firmware but it did not help. Rebooting back into the older 2.6.32-32 kernel solved the issue for me

The card is
$lspci -s 03:00.0 -v
03:00.0 Network controller: Intel Corporation PRO/Wireless 5100 AGN [Shiloh] Network Connection
        Subsystem: Intel Corporation Device 1211
        Flags: bus master, fast devsel, latency 0, IRQ 31
        Memory at f4300000 (64-bit, non-prefetchable) [size=8K]
        Capabilities: <access denied>
        Kernel driver in use: iwlagn
        Kernel modules: iwlagn

and I am running lucid
$lsb_release -dr
Description: Ubuntu 10.04.2 LTS
Release: 10.04

The hardware is a Lenovo W500 laptop