use check box created in Excel 2003 opened in Excel 2007

[TommyB]

I have created a worksheet in Excel 2003 that includes check boxes. I have
users of that worksheet who are using Excel 2007 who are telling me they
cannot click on the box and enter a check mark. Any ideas why?

Thanks!

 

[Barb Reinhardt]

I wonder if the worksheet isn't protected.