IDC Materials Resources Calculator not calculating correctly

I'm using the "IDC Material and Resource Calculator (June 2012).xls" that's downloadable from the MRc4 Credit Resources page. I'm using it on a Windows machine with Excel macros enabled. Somewhere along the line, it stopped calculating correctly (if at all). I noticed this prior to my initial project review submittal, when checking the boxes for "Certified Wood Vendor Invoices." I had checked the boxes for 100% of of the invoices, but the Calculator only showed 11%. I went ahead and submitted my project for review anyway, along with a text document noting the oddity. I was granted the credit. Life was good. But... in the MRc4 review comments, the reviewer wanted additional product cutsheets to be uploaded (the calculator was showing 13%). Today, I went ahead and checked enough boxes to put me well in compliance, but the Calculator still shows the same 13%. I'm no Excel whiz (seriously), but I did download a fresh copy of the Calculator, clicked on the Cutsheet's cell, looked at it's formula, and then at the comparable cell in the completed spreadsheet. Both were similar (same basic formula, just a greater total number of rows in the one I've been working with). Any thoughts? I could just write them another "note" explaining the issue, but I'd prefer to have the thing just work. Many thanks.