I'm drawing a blank here....

I open a workbook containing macros
I enable macros
A macro called IntroMessage runs (displays a msgbox)

If I rename the IntroMessage sub, the workbook, upon opening, displays a
message that the IntroMessage macro cannot be found...then it doesn't open.

When I insert Application.Caller into the IntroMessage sub, the msgbox
displays the file name.

Here's my dilema:
There is no auto_open macro in the workbook
There is no workbook_open macro

What other option am I forgetting?
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Regards,
Ron

XL2002, WinXP