Excel 12 Add-In compatibility - registerXLL fails in Office2007
 

I'm testing our existing Excel Add-In for compatibility with Office 2007.
This is a C++ Excel Add-In that gets loaded thru a VBA xla module.
The xla module loads and starts up ok, but the call to register the C++
component fails. This uses a standard call that works with all previous
versions of Excel.
returnValue = Application.RegisterXLL(addinFileName)
where addinFileName is a string set to the C++ Add-In filename.
The value returned is "false".

Has something changed for the calling prerequisites for the registerXLL
function or is this function broken in the beta version?

Thanks!