Nobody was saying exactly what took the bloom off this rose, but there was plenty of gossipy guessing. With all the movies the two have made in the past 18 months (at least six), they were under stress and often apart. Friends said the couple aren’t even speaking, but they’re still scheduled to shoot ““Duets’’ together this fall. The movie is to be directed by Gwyneth’s dad, Bruce Paltrow, who always warned his daughter not to marry an actor. Maybe Gwyneth finally decided that Father knows best.