If there are differences in ordered/invoiced values between reports, check:
1. Are all sales invoices in posted status - if they are in outstanding or completed status they will not show on some reports
2. If the report is looking at sales order values or sales invoice values - if you are comparing a report that shows sales orders to one with sales invoices there may be a difference if some orders have not been invoiced yet.
3. The dates on the criteria tab - please check if one is showing order date and the other invoice date (note invoice date pulls from the completion date not creation date)