PowerCLI Bug?

If I run the following:

$task = stop-vm -vm "vmname" -runasync

$task|select id

I get something like:

Id

--

Task-task-1283

If I run the following:

$task = move-vm -vm "vmname" -datastore "datastorename" -runasync

$task|select id

I get something like:

Id

--

In the move-vm example, the "id" is $NULL wherein the stop-vm or start-vm returns a valid task object.

I am running VMware vSphere PowerCLI 5.0.1 build 581491

The VC target is running VMware vCenter Server Version 4.1.0 build 491557

Thanks,

Keith