Just did a fresh install of 4.0 from the release CD on a Sunfire V100,and as soon as I did "ifconfig dc1 up", I got this message:
dc0: failed to force tx and rx to idle state
This time I hadn't even gotten around to setting up the network orforcing the speed and duplex, so it's not what I'd previously suspected...
I would still like to know what causes this, and whether it's something to worry about.