I submit this strange behavior, it is not the first time that it happens to me.
My networks adapters (an Ethernet card and a Wlan card) are both configured by the standard configuration tool.
They works fine also when they are together up running.
But ``sometimes'', as I'm logged in as a normal user, after i switched off my Wlan adapter while Ethernet keeps running, two unexpected behaviors rise.
The DNS for the resolution are lost, i.e. the entry in /etc/resolv.conf is erased.
Then when I try to reset DNS i cannot login anymore as root. Password seems lost and it is not blanked. Since I'm not able to become superuser I can't check logs and such others things.
The only way to solve this is to reboot the system in rescuing mode with a LIVE cd and to perform a classic password resetting.
I've never encountered this issue in other distributions i use to work with.
Anyone has some suggestion?