According to VMware vCenter Server 4.1 Update 2 Release Notes(http://www.vmware.com/support/vsphere4/doc/vsp_vc41_u2_rel_notes.html),
the loopback entry in the /etc/hosts file of the virtual machine might change to 127.0.0.1 <Host_Name/Alias> localhost.localdomain localhost ,and same thing has happened my machine .
I know I can fix it to 27.0.0.1 localhost.localdomain localhost so that some applications will fail.
But in I think this solution is only for a guest OS and applications on this guest OS.
I'm worried about some bad influence to cluster action,heartbeat for HA. OR do I have to configure another file or something if I change hosts file like above.