Animation of people (Heroes of Might and Magic 5)

Please tell me this is a bug or so conceived? During a small splash-panels, when the characters speak their mouths do not move. During a full-fledged cutscenes, everything is fine. Game steam license. At first thought it was due to official localization, as the incentive it in English sold, although officially it localized. Very good, not perfect without him, but the mouths still don't move. It is so conceived?