The Rolling Stones' recent stop at a Paris recording studio continues to be something of a mystery. Mick Jagger tweeted that the group "Had fun in Paris studio this week!," but no one's saying exactly what the group was doing there with Detroit-born producer Don Was -- if it was recording new material, working on its upcoming 50th anniversary documentary that will air on HBO this fall or, according to some report, remastering songs for a 50th anniversary compilation that's also expected to be released in the fall. During the unveiling of the coffee table book "Rolling Stones 50" earlier this summer in London Jagger promised that the Stones would play live "in the autumn," but no dates have yet been announced...Meanwhile the Stones are rolling out "Charlie is My Darling -- Ireland 1965," a notorious unreleased tour documentary from early in the group's career. The film, which includes concert, backstage and off-stage footage, will be premiered at the New York Film Festival on September 29 and October 3 and released on DVD and Blu-ray on November 6.