Comment 80 for bug 276990

This seems to be another issue not associated with this bug. I think you should file a separate bug report. This used to happen when I tested the daily builds of the iwl4965, I would load the driver and some sort of issue with mac80211 or cfg80211 would make my machine kernel panic. Try unloading all the modules

sudo modprobe -r iwlagn
sudo modprobe -r cfg80211
sudo modprobe -r mac80211

then uninstall backports (use completely remove in synaptic or aptitude purge from the command line) and restart.
Then reinstall backports and immediately restart after it is finished installing.

It worked for me when backports failed the first time.