I\'ve got a Workbook_Open event macro (and it\'s in ThisWorkbook) that doesn\'t always run.
This happens when a workbook is closed with an Application.EnableEvents set to false, and then you open another workbook within the same instance of excel opened. To avoid this, make sure that all of your processes that disable events, reenable them before terminating. Special attention to "End" commands, error handlers and "exit sub" sentences in the middle of your program.