Password protecting .xlsm workbook created in Excel 2003

The attached .xlsm workbook (password ABC) was created using Excel 2003 'Save As' from a similar .xls workbook.

I was under the impression that a 'Password Protected Workbook' (Structure and Windows) could not be opened without the password. When I attempt to open the Workbook, I am prompted for the password. The workbook opens with ANY password I enter, including just the Enter key.

For comparison purposes, the attached .xls workbook (password ABC) behaves as I expect. It only opens when the correct password is entered.

Can someone please explain this behavior to me. Excel 2003 is the only version I have access to.

Lewis

Thanks Trevor, Problem Solved.

I wasn't confusing the two, I was unaware that there was a difference.

Lewis