To all our users: Software evolves, and old versions cannot be supported forever. Windows XP was released more than 12 years ago, and Office 2003 was released more than 10 years ago.
Because of all the infrastructure involved (Windows APIs, COM and .NET, inability to use the Ribbon and Task Pane in Excel 2003), it is becoming ever harder to build a single application that will run on Windows 7 and 8 and also Windows XP, or a single add-in that will work in Excel 2013 and also Excel 2003. We have to focus on the future rather than the past.
Microsoft is officially ending support for Windows XP and Office 2003 on April 8, 2014. Frontline will also officially end support for Excel 2003 on that date.
If you are still using Windows XP and/or Office 2003, it is definitely time to upgrade.