Okay, let's try this:
1) Open the existing workbook.
2) Click on the Office Orb
3) Click "Excel Options"
4) Click "Advanced" in the left pane
5) In the left pane, scroll down to "Display options for this workbook"
6) Check the box that says "Show sheet tabs"
Right now, I haven't found a way to check it for everything, if it's a problem for multiple workbooks.
Hopefully this solves your problem
