Variable Values Lost When Executed via group policy shutdown

We're running windows 2008 R2, powershell v2.

I have a script that runs just fine when I execute it manually in powershell.

If I call the same script from the group policy, shutdown powershell scripts the variables within the script lose their values.

If I shutdown the server the scipt is executed but the values of the variables in the script are lost. There is no looping in the script.

Thanks,

Dan