Commission Regulation (EC) No 499/2006 of 28 March 2006 on initiating an investigation concerning the possible circumvention of anti-dumping measures imposed by Council Regulation (EC) No 769/2002 on imports of coumarin originating in the People's Republic of China by imports of coumarin consigned from Indonesia and Malaysia, whether declared as originating in Indonesia and Malaysia or not, and making such imports subject to registration