I am stumped by this one. I have some VBA code in an Excel file that uses Microsoft.ACE.OLEDB.12.0 to retrieve a row from a SharePoint 2010 list. If I open the Excel file from a mapped drive and run the code, it works flawlessly. If I copy the working Excel file to my local hard drive and run the code, i get an exception "Invalid Argument" when the connection is opened.