2006-12-18 
どうやら、NICのeepromの問題のようです。以下のバグレポートにあるように、下のスクリプトを一度実行することで直りました。 
http://bugzilla.kernel.org/show_bug.cgi?id=7450 
http://bugzilla.kernel.org/attachment.cgi?id=9400&action=view 
#!/bin/bash

if [ -z "$1" ]; then
echo "Usage: $0 \<interface\>"
echo " i.e. $0 eth0"
exit 1
fi

if ! ifconfig $1 > /dev/null; then
exit 1
fi

dev=$(ethtool -e $1 | grep 0x0010 | awk '{print "0x"$13$12$15$14}')

case $dev in
0x108b8086)
echo "$1: is a \"82573V Gigabit Ethernet Controller\""
;;
0x108c8086)
echo "$1: is a \"82573E Gigabit Ethernet Controller\""
;;
0x109a8086)
echo "$1: is a \"82573L Gigabit Ethernet Controller\""
;;
*)
echo "No appropriate hardware found for this fixup"
exit 1
;;
esac

echo "This fixup is applicable to your hardware"

var=$(ethtool -e $1 | grep 0x0010 | awk '{print $16}')
new=$(echo ${var:0:1}`echo ${var:1} | tr '02468ace' '13579bdf'`)

if [ ${var:0:1}${var:1} == $new ]; then
echo "Your eeprom is up to date, no changes were made"
exit 2
fi

echo "executing command: ethtool -E $1 magic $dev offset 0x1e value 0x$new"
ethtool -E $1 magic $dev offset 0x1e value 0x$new