The AddIn I developed in Excel 2007 now works on 2003 and 2002, but fails
when installed withe Excel 2000. The workbook will load just fine when I
strip all vestiges of VBA macros from it, but as soon as I try to enable the
AddIn it says, "Sorry, Excel has encountered an error and has to close.

Any idea what is causing this? For example, is this a known, basic
incompatibility issue? Or, perhaps a few techniques or functions that one
can avoid?

To be clear, the Addin was saved as an Excel97-2003 xla file under 2007.

I am trying to get my user to upgrade to a latter version, but he refuses to
consider Office 2007 because of what he has read about compatibility and
changes in the user interface. I've now asked him to consider Office 2003.
This brings me to another question, will Office 2003 Basic work, or would he
have to get the Pro version? What does Basic leave out?


Ed