Exception with Remote Powershell ADInvalidCredentialException

Hi Techies,

I am trying to get Mailbox statistics using Remote Powershell as an Administrator.

I have gave privileges to Administrator , but even after my powershell command is retrieving data some time and sometimes shows error like

Active Directory operation failed on sys.sys2008.co.in. The supplied credential for 'HYP2008\Administrator' is invalid.
    + CategoryInfo          : NotSpecified: (:) [], ADInvalidCredentialException
    + FullyQualifiedErrorId : D3F53D22
    + PSComputerName        : ComputerName

It is not happening all the time. Periodically my command works.

This is my command :

Invoke-Command -ComputerName ComputerName -Port 5985 -Credential $Cred -Scriptblock{Add-PSSnapin Microsoft.Exchange.Management.PowerShell.E2010;Get-MailboxDatabase -Status | Select-Object Name, Mounted}