Will Arbitron's headache over the rollout of its portable people meter service ever end?

The latest regulatory body to scrutinize the PPM service for its affect on minority radio stations is the Government Accountability Office. Earlier this week House Judiciary Chairman John Conyers (D-Mich.) and several other members asked the GAO to investigate the PPM and whether it undercounts minorities.

The GAO joins a number of government bodies that have opened up inquiries into the PPM, including the Federal Communications Commission and the House Committee on Oversight and Government Reform. In July, the Florida Attorney General filed suit against Arbitron to prevent commercialization of the PPM service in Miami, prompting Arbitron to move up release of the data by two days. Earlier this year, Arbitron settled with three state attorney generals in New York, New Jersey and Maryland.

Arbitron responded to the GAO inquiry the same way it has responded to other similar government inquiries. "As always, Arbitron welcomes every opportunity to discuss the PPM technology, service and our sampling methodology. We continue to have a dialogue with key members of Congress as well as other interested parties, and look forward to helping the radio industry as a whole remain competitive in the current media marketplace," the company said in a prepared statement.

Regulators may be the least of Arbitron's worries. In the company's recent earnings call, it said that Univision Communications has decided not to subscribe to the service in all the markets where it has radio stations. While Univision continues to encode its signals in New York, Los Angeles, Chicago and San Francisco, it has refused to encode in Miami, San Diego and Phoenix, leaving buyers without a complete picture of radio listening in those markets.

"We subscribed initially expecting Arbitron to provide reliable audience estimates in those markets. We stopped using the estimates due to the flawed sample. We are hopeful Arbitron will address the issues identified by Attorneys General in New York, New Jersey, Maryland and Florida as well as numerous members of Congress," Univision said in a statement. "We need reliable information. Once that is available, we will subscribe to the service and use the data."

In addition to Univision, Arbitron has also been under pressure from the National Association of Black Owned Broadcasters, the Spanish Radio Association and the Minority Media and Telecommunications Council.

Arbitron's PPM is currently commercialized in 20 markets.