Unable to apt-get update most of today with amd64 on Acer 5253 notebook. I've got it plugged into an external keyboard and monitor, and usually have a wired network and wireless both active since sometimes I do live boots and don't want to bother setting hidden wireless WPA security. Been doing this for a year O.K.
Today apt-get update gets all screwed up trying to resolve the sources.list entries. Then even screwed up Firefox accessing this forum. Refresh failed.
Tried disabling the wireless no help. So shut down altogether.
Booted up, disabled wireless first, then apt-get update running O.K., forum O.K., and Firefox has no problem accessing tabs.
?
Of course when both are active and I've got the problem, network is screwed up, hence can't do a ubuntu-bug network-manager since it can't log onto launchpad.....