Ping issue with virtual machines

Hi,

Im having a issue while trying to ping a computer.

I have a physical server which runs 2 virtuals and also another physical sbs2003 server which we are planning to migrate. Both physical servers can ping each other and can be seen on the network.
But both physical servers can not ping the virtuals but they can be seen on the network and both virtuals are added to the domain.
Both virtuals can ping both physical servers and also browse the network.
Both virtuals are on the SBS2003 domain.

I have another site with exactly the same set-up which had exactly the same problem, however i was able to resolve the issue at site 1 by adding a rule to the virtual servers firewall to allow connections from a specified range of (internal) IP addresses, but on site 2 i am having no such luck as adding the rule to the firewall is having no effect.

I have been able to (i think) locate the issue to be the firewall on both the virtual's and exclusively to the domain side of the firewall as when i disable the domain firewall everything works as expected.

Any advice on this would be great.

Thanks