The most common solution to this problem is to disable NTP and install Vmware-tools. However, this is not an option for me, as I have no X server on my guest.
I have added the following kernel parameters:
clock=pit nosmp noapic nolapic
I have disabled acpi on the host. I have disabled frequency scaling on the host.
Host is a quad core running Ubuntu Hardy 64bit. Guest is redhat running 32bit. Host clock gains 5 minutes, guest clock gains 1. As the guest is an email server, time is critical. A combination of the above solutions has fixed the clock issue on most of my guests, but this one remains illusive.