Comment 15 for bug 183673

the same here
updated to 8.04 from 7.10
network-admin is locked or crashed (sudo can't open it), unlock button greyed all the time
eth0 have no mac address and work in roaming mode, firewall have open ports (i've tried 3 firewalls, looks like iptables don't care), local network spamming and i can't stop it.
when i try to open ppoe or eth0 config in network manager - it tell me that device is not found.
but i have internet

And it's when my 7.10 was tuned and works perfectly :(

how to unlock that interfaces and protect my computer?
i have this policykit installed:

ii policykit 0.7-2ubuntu7 framework for managing administrative policies and privileges
ii policykit-gnome 0.7-2ubuntu1 GNOME dialogs for PolicyKit