Using SharePoint 2007, Excel 2010.

I want to be able to export a linked spreadsheet from a sharepoint list so I use Excel 2003 to export the list to a 2003 format spreadsheet.

I then use my normal Excel2010 to open up the spreadsheet and make sure I save it in the 2003 format.

When I make changes to the spreadsheet and then do a "synchronize with SharePoint", there seems to be extra records inserted into the SharePoint list as opposed to just updating the existing records I want changed.

Does anyone have an idea of why this would be happening?