One of the initial issues I had with Virtual Center is that it did not always show the correct firewall settings. The command esxcfg-firewall seemed to be the authority on open ports. By executing 'service mgmt-vmware restart' at the command prompt it syncs up VC with esxcfg-firewall. If you decide to script this and plan on having commands after this, you will want to add a 'sleep 20' command on the next line so that the VM management service has a chance to finish the sync.