To solve this problem with
Atheros Communications, Inc. AR5006EG 802.11 b/g Wireless PCI Express
Adapter (rev 01)
i installed
http://snapshots.madwifi.org/madwifi-ng/madwifi-ng-r3067-20071220.tar.gz
then, in the file
/etc/modprobe.d/blacklist
add the following line:
blacklist ath5k
and reboot.
Bye