Data Shuttle is not finding all columns in the source sheet


I am trying to use data shuttle to upload data from an excel file in SharePoint but when I get to the mapping part, the column names are completely different from the source. Almost as if it is not pulling the data from the sheet I specified, but a different one. I am using the second tab of the excel sheet and some of the options for column mapping aren't even in the workbook. Any help would be greatly appreciated.