Excel 2003, XP and Vista

I've been releasing VBA code through Add-Ins for years... Then last week any
new macros added can not be found in the Addin: Err Msg: The macro
'Addinname.xla!HelloWorld' cannot be found.

The code executes inside of VB editor but can not be referenced outside of
the editor???

Simple test: 1.New workbook,VB editor - Create HelloWorld, Assign macro to a
Menu button, Create Add-in via SaveAs, Try to execute via the button.

Any ideas would be greatly appreciated.