That fixed it thanks!

How to fix it with Debian 7.0:
sudo cp cgminer-3.2.1/01-cgminer.rules /etc/udev/rules.d/
sudo service udev restart
Now unplug and plug again the usb erupter.
Restart cgminer and it should work.
copy the 01-cgminer.rules into /etc/udev/rules.d/ and restart udev.
the permission of the cgminer executable doesnt make any difference