License file download from SERVER to vCenter Server failed due to exception: vim.fault.HostConnectFault.

Hello all:

I  am trying to add a Esxi 5.0 to a new installation of Vcenter. I was  able to add my other hosts which are running ESXi 4.1, however, when I  try to add this new installtion (everything else is wokring) I am  getting this error:

License file download from SERVER to vCenter Server failed due to exception: vim.fault.HostConnectFault.

Anyone know why?

I tried to add a license key at the time of adding, or even trying evaluation mode - both came up with the same error.

Any help would be greatly apprecaited.

Thanks