Script Scheduling error

I have a script with I use to create a excel file, I can run the script in server without any issue it creates the result file. But when I schedule the script, it’s not working.. I get the following error.. Can someone help me to fix this issue?

I am using.. Windows 2008 R2 Standard Office 2010

Error

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Windows PowerShell Transcript Start

Start time: 20130724072922

Username  : Test\subash

Machine             : LAB01 (Microsoft Windows NT 6.1.7600.0)

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Transcript started, output file is C:\TEMP\Temp.log

Exception calling "InvokeMember" with "6" argument(s): "SaveAs method of Workbook class failed" At C:\temp\test.ps1:40 char:42 + [void]$wkbk.PSBase.GetType().InvokeMember <<<< ("SaveAs",[Reflection.BindingFlags]::InvokeMethod, $null, wkbk, $sfile, $newci)   + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException    + FullyQualifiedErrorId :  otNetMethodTargetInvocation **********************

Windows PowerShell Transcript End

End time: 20130724072930

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