Nielsen Media Research told clients on Friday it was again postponing the release of its average commercial minute ratings data.

The data originally scheduled to be released in October was delayed last month until Dec. 11 because of several issues, including problems in generating ratings for cable and syndication. No new release date was disclosed.

Nielsen had been asked in June by the broadcast networks and one media buyer to create a new ratings system based on how many viewers, on average, watched the commercial minutes within individual programs. The commercial ratings were designed to give advertisers a better idea of how many people were watching the spots they buy. Since the commercial ratings plan was announced, it has been bathed in controversy over the accuracy of the data, details of how it’s put together and whether they’ll include commercials seen on a delayed basis by viewers using digital video recorders.

In its note to clients, Nielsen said the new postponement was temporary. It said that on Oct. 30, it sent a new analysis of DVR playback to clients that stimulated new debate about whether commercial ratings should be based on the existing three ratings streams-live viewing, live viewing plus one day of DVR playback, or live viewing plus seven days of DVR playback, or some other combination.

A special client meeting will be held later this month to discuss the topic, Nielsen said.

Nielsen said the postponement will also help it take steps to address the issues of providing measurement for cable and syndication clients. Most cable networks decided not to participate in the commercial ratings plans because they didn’t want inaccurate-and possibly unflattering—data in the marketplace.

“Nielsen is undertaking significant work in both of these areas and that work is well underway,” Nielsen said it its note. “The impact of the temporary delay in releasing this data brings the timeline of all these initiatives closer in alignment.”