cfspreadsheet breaks Excel's "Format Cells..." functionality?

Hi everyone,

I am working on moving a CF7MX project to CF10 and one of the changes involve updating some code used for generating csv files so that it makes use of the CF spreadsheet functions.  One thing I noticed was that I can no longer use the "Format Cells..." functionality with xls files generated with the CF spreadsheet functions.

If I try it with any other file it works like a charm, but with these CF generated files clicking on the button shown above does nothing.  Is this a already bug known by Adobe? Is there a way to make this work?

Regards,

Miguel Arvelo