Problem with NetworkManager, Ubuntu Edgy Eft and the bcm43xx driver

[David R Mulligan <david mulligan shaw ca>]

I am writing this message partly in case others are having the same
problem.

If I leave my Dell Latitude D600 laptop with Dell 1450 wireless card
idle for a while, usually at least a couple of hours, I will start to
get this message repeated over and over in /var/log/messages "NETDEV
WATCHDOG: eth1: transmit timed out."  There are no other messages that
are obviously related and nothing else is logged between the netdev
messages.  When this happens my keyboard is dead and I am lucky if I can
shutdown my computer using the mouse to select shutdown (or anything
else for that matter.)

According to this thread network manager may be involved
http://lkml.org/lkml/2006/11/15/296 .  Either way my work around is to
disable wireless through the nm-applet left click menu.  Fn-f2 to
disable the radio is not enough to stop the problem from happening.
Since disabling wireless through nm stops the problem seems to indicate
that nm is in some way at least a catalyst for the problem.

Thanks,
David