"It's nostalgia not about the Soviet Union but about your past, about your childhood, (...) about your naive vision of the world around you," says dissident Russian director Kirill Serebrennikov on "Petrov's flu", his latest film set in the stagnant years before the collapse of the Soviet Union, presented at the Cannes film festival while he's under house arrest in Moscow. Serebrennikov -- who was also under house arrest when his last movie "Leto" picked up a prize at Cannes three years ago -- is in the running again for the Palme d'Or. SOUNDBITES