The number of songs being traded through Napster has dropped sharply since the company began policing its system for unauthorised music.
Napster users were downloading 50% fewer files as the company beefed up its screening technology, according to Webnoize.
Before upgrading its system to block access to infringing content, the average number of files shared per Napster user was 172. The average number is now 71.
Napster officials continue to disagree with the recording industry about the burdens the company must bear in policing its system for unauthorised content.
Napster told US District Judge Marilyn Hall Patel in a document filed on Monday that "critical disputes" had arisen with the recording industry.
The company says the record labels are wrong in thinking the March 5 federal court injunction meant Napster must search for infringing content even prior to proper notification from copyright holders.
Napster says it is unable to block some of the songs because the recording industry has failed to supply specific enough information. But the industry claims Napster's niggling over particulars is an attempt to buy more time.
On Tuesday, the company announced it had signed a deal with Gracenote, a company that maintains a database of more than 12 million musical works catalogued by artist and title, including spelling variations that may have slipped through Napster's system in the past.
After the screening technology began to make a dent in online trading, other services popped up on the internet with solutions to the barrier. These included several online "pig Latin" translators that turned Britney Spears, for example, into "Itneybray Earsspay."
At the request of Napster, file-sharing firm Aimster has now removed its pig Latin program from its website.