[CentOS] CentOS 6 guest OS does not detect reboot/shutdown signal from virt-manager

My setup is as follows:

Host OS: Debian Wheezy amd64 stock kernel (3.2), virt-manager v0.9.1

Guest VMs: A bunch of Linux based servers - CentOS 6, Debian 6/7, Ubuntu 12.04 (all amd64 with stock kernel). All of them defined using virt-manager GUI interface.

From the virt-manager, I am able to shutdown/reboot the Debian and

Ubuntu guest OSs but not the CentOS 6 guests.

For the CentOS 6 guests, I have to resort to "Force off"

I have looked at the syslog and messages log files but do see anything to correlate between host and guest OS.

Any pointers on how to debug this problem would be much appreciated.

Thanks,