I have a workbook with a "library" of macros. I open and close it
frequently. Since I have macro security set to "medium", I expect and
get the Security Warning diaglog box that says: "<fileName contains
macros. Macros may contain viruses", with Disable and Enable Macros
buttons.

All of sudden, I am now getting an undesired second dialog box with
the title Microsoft Excel. It says: "This workbook contains one or
more Microsoft Excel 4.0 macros. [....] Do you want to enable these
macros?", with Yes and No buttons.

Why am I now getting this second dialog box? That is, what might have
changed? More to the point, what I can do to get rid of it?

Of several workbooks that I have that contain macros, this is the only
one so far that produces the undesired second warning.

I am using and always have used Office Excel 2003. According to my
book, that is synomous with Excel 11, not Excel 4 (same as "4.0"?).

Recently, I did set my macro security to "very high" during some
experiments; and I might have saved the workbook in that state
inadvertently. But since then, I have set the macro security back to
"medium" and saved the workbook.

I use only some standard add-ins, namely the ATP and Solver. That has
not changed for a long time.

I do not believe I have made any changes to the "library" of macros,
which are in Module1. Recently, I did add some test macros in
Module2. I believe I had reopened the workbook without getting the
extra prompt since I added Module2. But honestly, I cannot be sure.

Nevertheless, when I cut-and-paste all of the macros to Module1 and
Module2 of a new workbook, then close and reopen the new workbook, I
get only the first Security Warning, as I expect. I do not get the
undesired second warning.

Moreover, returning to the "bad" workbook, if I remove Module2, the
second Microsoft Excel warning persists. It fact, it persists even
after I deleted all of the worksheets, which referenced some of the
functions, and added a new blank worksheet. Moreover, the undesired
second warning persists after I delete all unnecessary macros in
Module1. Those were test subroutines.

In summary, nothing I do or undo seems to remedy the problem in the
"bad" workbook. But the same macros copied into a new workbook do not
incur the undesired second warning.

Technically, I have already worked around the problem by cut-and-
pasting the macros to new workbook. But I would still like to
understand the situation so that I will know what to do in the future,
when perhaps the work-around will not be that simple.

Thanks for any insights.