CentOS virt - Jul 2009 - Loading default keymap error after a yum update...

Hi,
I'm running CentOS 5.3 on a XEN VPS.

After I yum update,
I've got this error on boot.

Press 'I' to enter interactive startup.
Cannot access the Hardware Clock via any known method.
Use the --debug option to see the details of our search for an access 
method.
Setting clock (utc): Thu Jul 16 18:54:50 CEST 2009 [ OK ]
Starting udev: [ OK ]
Loading default keymap (us): /etc/rc.d/rc.sysinit: line 396: /dev/tty0: 
No such file or directory
[FAILED]
Setting hostname localhost.localdomain: [ OK ]


is there a solution to that problem?
please help.
thanks.
Davide.