Comment 60 for bug 144621

I have the bug described, and also this other one probably more serious:
https://bugs.launchpad.net/ubuntu/+source/linux-ubuntu-modules-2.6.22/+bug/146191
which is probably the same as this
http://bughost.org/bugzilla/show_bug.cgi?id=1539
and has a patch as you can see.
PLEASE include the patch in the gutsy-updates. Please note that it is very recent and has not made it into the 1.2.22 intellinuxdrivers sources, it has to be applied over it.

For now you can have the fixed drivers with the following steps (not as difficult as others have suggested, in my case at least):
Download intellinuxdrivers package 1.2.22 sources:
wget http://www.intellinuxwireless.org/iwlwifi/downloads/iwlwifi-1.2.22.tgz
download the patch near to it
wget http://bughost.org/bugzilla/attachment.cgi?id=1264
rename it to something more sensible
mv attachment.cgi?id=1264 iwldrivers.patch
unpack the driver and apply the patch
tar -zxvf iwlwifi-1.2.22.tgz
cd iwlwifi-1.2.22/origin
patch <../../iwldrivers.patch

Now download kernel 2.6.22 sources, these are needed to compile the driver. The kernel headers, as others have noticed, are not enough.
I think: apt-get linux-source-2.6.22
this goes in /usr/src/linux-source-2.6.22
unpack the sources if they are compressed (I don't remember)

Now as root, go back to the directory iwlwifi-1.2.22
export KSRC=/usr/src/linux-source-2.6.22
make
install
depmod
now you should have the new drivers, installed in parallel with the ubuntu ones, that is in a separate directory, probably in
/lib/modules/2.6.22-14-generic/kernel/drivers/net/wireless/
while the ubuntu older ones are probably in
/lib/modules/2.6.22-14-generic/ubuntu/wireless/iwlwifi/iwlwifi/origin/
Make sure modprobe iwl4965 really loads the new drivers and not the old ones. Maybe rename the old ones.