Assciators of users in Powershell

Hi,

I am using the following to know the groups of the user using powershell.

Associators of {Win32_UserAccount.Name='$username',Domain='$domainname'} WHERE AssocClass=Win32_GroupUser

On some windows 2008 machines it passes and on some it fails.

If someone could shed light as to why it timesout/fails, it would be great.

Also is there any logging provided by Windows machines by default where why these powershell queries fail or behave ?

Thanks

Randeep