VirtualMachineRelocateDiskMoveOptions is just an enum.

That value was added in vSphere 4.0, any chance you are using an older WSDL file?

I do recall that if you were running unlicensed, there were some SDK features that were disabled. Or so I think I remember. I never run without a license, so I never verified it myself. However, this wouldn't stop you from seeing VirtualMachineRelocateDiskMoveOptions in your IDE. You'd just get a SoapFault with some SDK calls.