Description of problem:
I've been running fc6 on kernel-2.6.19-1.2911.6.5.fc6, yesterday I made an 
upgrade to kernel-2.6.20-1.2933.fc6 by means of yum-updatesd, After update I
wasn't able to connect to internet, apparently eth0 is unable to connect because
my ip is already occupied by other host. 

Network can be manually activated by means of system-config-network:

[root@lterpan etc]# /etc/init.d/network stop
Interrupción de la interfaz eth0:                          [  OK  ]
Interrupción de la interfaz de loopback:                   [  OK  ]
SIOCGIFFLAGS: No such device
[root@lterpan etc]# /etc/init.d/network start
Activación de la interfaz de loopback:                     [  OK  ]
Activando interfaz eth0:  sysfs class device: Permission denied
Error, algún otro host ya usa la dirección 192.168.X.XX.
                                                           [FALLÓ]
[root@lterpan etc]# ping 192.168.X.XX
connect: La red es inaccesible
[root@lterpan etc]# system-config-network
[root@lterpan etc]# ping 192.168.X.XX
PING 192.168.2.45 (192.168.X.XX) 56(84) bytes of data.
64 bytes from 192.168.2.45: icmp_seq=1 ttl=255 time=0.913 ms
64 bytes from 192.168.2.45: icmp_seq=2 ttl=255 time=0.225 ms

--- 192.168.X.X ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 0.225/0.569/0.913/0.344 ms


Version-Release number of selected component (if applicable):

kernel-2.6.20-1.2933.fc6.i686

This problem is also described elsewhere (see
http://www.unixboard.de/vb3/showthread.php?t=28733)

How reproducible:

I would appreciate your help

Always

Steps to Reproduce:
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Actual results:


Expected results:


Additional info: