Mentioning the highly successful Infernal Affairs (無間道), Peter Tsi, a Hong Kong film fest guy says, says: "To be screened on the mainland, Hong Kong films have to pass stringent censors and the Chinese government will have the right to remove sections they deem offensive or 'politically incorrect,' he said.

Taboo subjects such as supernatural or superstitious beliefs, explicit sex scenes, politics and homosexual love stories are hard to get past the censors.

Infernal Affairs -- co-produced with a state-owned studio -- was shot with two different endings. In Hong Kong, the bad guy gets away with murders under the nose of the befuddled police. In the mainland version, the bad guy's cover is blown and is promptly arrested."