I think also you must change the actors string by
movieDetails.Cast += Acteurs.Groups["nom"].Value;
(Old value is movieDetails.Cast += Acteurs.Groups["nom"].Value + " est " + Acteurs.Groups["role"].Value.Trim();)
This optimize the search by actors in MediaPortal interface.
(Sorry for my english...)
Moreover, with the "nom est role" syntax, import in MePo DB is incorrect as the name/role pair appears to be splitted by the "as" word. Hence, DB is filled with actors with name "John Doe est Whoever" and no role, instead of "John Doe" as "Whoever".
David LDD