LOS ANGELES (Reuters) - The makers of Dancing With the Stars ran through regular rehearsals on Sunday night for this weeks finale even as controversy centred on contestant Bristol Palin and mystery surrounded an envelope received by the popular show. Palin, daughter of Tea Party favourite and former Alaska Republican Governor Sarah Palin, has made it to the finals of the top-rated TV program despite a season of low scores, raising the ire of many of the programs loyal fans. One Wisconsin man was so angered by Palins advancement last week that he fired at his TV with a shotgun, fuelling a 15-hour standoff with police, authorities said. Late on Friday, the programs producers received an envelope containing a white substance that set off warning bells of an anthrax scare. Police and fire officials determined it was talcum powder. Several media reports, citing unidentified sources, said the envelope was addressed to Palin. But officials at the ABC television network, which airs the program seen by nearly 20 million viewers weekly, issued a statement saying it was delivered to the shows production office. Measures were taken to secure the area and ensure the safety of personnel. Ultimately we were advised by the (Los Angeles Fire Department) that the substance was determined to be talcum powder, ABC said. A network spokeswoman had no comment beyond the statement. Dancing pits celebrity contestants and professional partners against each other weekly in ballroom dances. A panel of judges scores each contestant, and audiences can vote via phone or the Web. As a result, fan ballots and popularity often influence who stays on the show more than a contestants dance moves. As the field narrowed to three - Palin, movie star Jennifer Grey and TV actor Kyle Massey - critics charged that the 20-year-old Palin benefited from her mothers popularity because her scores had routinely fallen behind others, such as singer Brandy, who was kicked off last week. Producers have defended the voting and Palin has hit back at critics, attributing her success to hard work. Many contestants over the years, including talk-show host Jerry Springer and actress Cloris Leachman, have seen fan voting keep them in the competition when their feet seemed to fail. Dancing completes its season with a performance show on Monday and a final episode on Tuesday when a winner is named.