Workflow returns vlan=0 for all portgroups with vCenter 5.5 Update 1c

I am running this simple workflow and vlan is always 0 even though there is no vlan that has vlan 0. This workflow is running well on a vCenter installation prior to update 1c. I can set the vlan but I canot query it. I have tried with the "build in" Windows vCO and with the vCO appliance but the result is the same. Anybody else seeing this? Maybe someone wants to try?


dvs is input parameter of type VmwareDistributedVirtualSwitch


for each (var pg in dvs.portgroup)
{
    if(pg.config.defaultPortConfig.vlan instanceof VcVmwareDistributedVirtualSwitchVlanIdSpec)
    {
        System.log("Portgroup name: " + pg.config.name);
        var pgVlan = pg.config.defaultPortConfig.vlan.vlanId
        System.log("vLAN:" + pgVlan);
    }                
}