OK this works.
My mistake, the concerned character is in fact a Windows character (CP1252)
I hadn't noticed when I converted my schema to a text file.
> -----Message d'origine-----
> De : Hallvard Breien Furuseth [mailto:h.b.furuseth@usit.uio.no]
> Envoyé : lundi 20 octobre 2008 19:39
> À : Emmanuel Duru
> Cc : openldap-its(a)OpenLDAP.org
> Objet : RE: (ITS#5755) Schema file not always converted to LDIF and
> slapdwon't restart
>
> The problem is the 8-bit Latin-1 character in the certificate's DESC.
> It works if you convert the schema file to UTF-8.
>
> Slapd should have refused to start with a non-UTF-8 attribute DESC.
> Possibly that should wait for OpenLDAP 2.5 though, and just log a
> warning for now.
>
> --
> Hallvard