One well-placed source told Page Six that producers on "Vicky Cristina Barcelona," Scarlett Johansson's latest Allen flick, have been grumbling that "Scarlett isn't the same . . . She's turned into the biggest prima donna." The source added that the same producers raved about working with her on "Match Point," when "everyone said she was a sweetheart . . . now they say, 'Scarlett's let it (being Woody Allen's muse) get to her head.' "