I've have a recurrent problem in a somewhat huge Excel Vba application.

For 3 (out of more than a hundred) comboboxes, defining listindex doesn't
work anymore. It is not the last three controls in my form (not even the last
three comboboxes).
To be more precise, it works the first time, after i've made modifications
in VBA but it doesn't work anymore if i save the file, quit Excel and rerun
it.
It works perfectly if debugger is on (ie i enter visual basic editor and
type the password which protects my project).
Error message is : -2147417848 (80010108) ListIndex Method for IMDcCombo
object has failed (La méthode 'ListIndex' de l'objet 'IMDcCombo' a échoué)
and is followed by an Excel crash...

If i comment the 3 lines of code involved, program runs smoothly, Comboboxes
are initialized (with Additem Method) and i can select manually every value.

Problem occurs with XL XP (Windows XP Pro), XL 2003 (Windows NT), XL 2007
(Vista) in compatibility mode.
Problem doesn't seem to occur with new XL 2007 format but if i convert the
file back to XL 2003 format problem reappears!

It does not seem to be related with unqualified Office references (as
described in MS Q319832 Bulletin : i do not use in my program other Office
applications, error is present after leaving Excel (it crashes :)), it runs
with no reference to Microsoft Office 11 object Library)

I've spent a lot of time to try to find a workaround without success...If
somebody has an idea I will try it!

Thanks

GD