You cannot locate an Excel 2007 workbook when you specify http://localhost in the workbook URL parameter for an Excel Web Access Web Part

When you specify http://localhost in the workbook URL parameter for an Excel Web Access Web Part, you cannot locate the Microsoft Office Excel 2007 workbook. This issue occurs if you create an Excel Web Access Web Part on a computer that resides in a farm environment and is running Excel Services for Microsoft Office SharePoint Server 2007.

This issue typically occurs in a SharePoint Server 2007 farm environment in which the Web front-end server and the Excel Services are located on separate computers. In this case, the http://localhost URL maps to the Web front-end server and not to the computer that is running Excel Services.

We recommend that you specify the full URL to the workbook in the workbook URL parameter.

This behavior is by design.