error eth0 has different MAC address than expected, ignoring after install and reboot

Dear Sir,

I'm already Install Cento 5.6 64 on my pc and networking card working properly, then I install xen with this tutorial : http://howtoforge.org/paravirtualization-with-xen-on-centos-5.6-x86_64.I get problem when edit /boot/grub/menu.lst change the default from 1 to 0,after that i reboot the pc and get the error message : error eth0 has different MAC address than expected, ignoring

I already change or delete hwaddr ifcfg-eth0 the problem still same
any idea for me??

Thanks


Rasyid.