Get-Stat : 21/05/2012 12:34:35    Get-Stat        Object reference not set to a
n instance of an object.
At D:\rep\Perf.ps1:6 char:18
+ $stats = Get-Stat <<<<  -Entity $vms -Start $start -Stat $metrics
    + CategoryInfo          : NotSpecified: (:) [Get-Stat], VimException
    + FullyQualifiedErrorId : Core_BaseCmdlet_UnknownError,VMware.VimAutomatio
   n.ViCore.Cmdlets.Commands.GetViStats