New-VIProperty Config.Host.Value InvalidProperty

vCenter 4.1 Update 2

PowerCLI 5.1 Release 1

I can successfully retrieve VMHost's IDs via:

Get-VMHost | Select Name,@{N='VMHostID';E={$_.ExtensionData.Config.Host.Value}}

I can also (appear) to successfully create a VIProperty for VMHostID with:

New-VIProperty -Name VMHostID -ObjectType VMHost -ValueFromExtensionProperty Config.Host.Value

However, when I try to use it I am greeted with an exception and no values in VMHostID

Get-VMHost | Select Name,VMHostID

CategoryInfo : [Get-VMHost], InvalidProperty

FullyQualifiedErrorId: Client20_ExtensionDataHelper_GetExtensionDataByObjectContent_ViError,VMware.VimAutomation.ViCore.Cmdlets.Commands.GetVMHost

I get the same result on multiple vCenters of the same version. Creating VIProperties from other VMHost extension properties work without issue.

Is anyone able to reproduce this?