PowerEdge R710 IPMI with Vmware ESX4

I am trying to setup the Power Mangment portion of our VMware ESX4 servers running on a Dell R710 but not having any luck. ESX4 requires IPMI to be configured first before I can place the servers in standby and bring them back out.

[Setup]

Ports 1 and 2 are configured for the iDrac 6 express and are configured for the vMware vConsole. Also the vConsole and idrac6 are configured on the same vlan with trunking turned off, and are in the same subnet range.

vCenter Server is running on Windows Server 2008 with the  firewall off and on the same subnet as the vConsole and iDrac6

[Issue]

I am able to successfully connect to the idrac interface from my machine, but i can not ping the idrac ip address from the ESX4 server. However, I can ping other idrac ip address that are on my other two ESX servers that I am having the same issue with. I can also succesfully query the IPMI on any of the servres from my machine.

When I attempt to configure the IPMI / iLO Settings i get the following "The request failed because the remote server 'vcenter server name' took too long to respond. (The command has timed out as the remote server taking to long to respond.)

Any help is appreciated,

Thanks

Dan