New legal documents filed by song-swapping company Napster provide an uncharacteristic glimpse behind closed court doors, showing the company chafing for months under the hands of the court's technical adviser. The company is appealing an injunction that would require it to block 100 percent of works identified by recording companies as copyrighted. That ruling has temporarily been put on hold by the appeals court. But Napster is also contending that federal court Judge Marilyn Hall Patel gave far too much power to her appointed technical adviser, who over the course of a few months grew from a court adviser into a de facto chief technical officer for the file-swapping service. "Napster found its core file-sharing service essentially in receivership -- answerable to [technical adviser A.J.] Nichols, dependent on his approvals and certifications, and beholden to him for any possibility of judicial redress," the company's lawyers said in the documents filed Tuesday. Nichols "generally interject[ed] himself into the day-to-day operations of Napster," they said. Appointing a "special master" in cases that treat highly technical issues is a standard practice in courts. The most prominent was probably Judge Thomas Penfield Jackson's appointment of law professor Larry Lessig to review issues in the Microsoft antitrust case. Nichols himself served as a court adviser in Sun Microsystems' suit against Microsoft. The criticism of Nichols' role is just one small part of a 96-page document with which Napster hopes to persuade the appeals court to give it some small margin of error in its blocking. Former CEO Hank Barry said that the new filters block more than 99 percent of songs, but the company could not live with a 100 percent standard. But the history outlined in the documents also gives a daunting look into the development process of what still stands to be one of the closely watched subscription Internet services ever. Napster still plans to launch its paid service soon, which will include some of the technology developed under the close scrutiny of the court. The appeals court's review of the court-supervised development process will ultimately affect the shape of the subscription service as well. The focus of Napster's past few months, and of this round of court documents, has been the development of a new filtering system that blocks file transfers by using the unique characteristics of sound files. According to the court documents, this filtering system took the work of 40 engineers and about $2.25m to develop, even outside the costs of licensing the basic technology from software company Relatable. The schedule for developing that system was up to the court, however. In a report to the court in early May, Nichols noted that Napster's initially sieve-like filtering system was getting better and that the company hoped to finish the fingerprinting filter by 8 June, an "aggressive" schedule. At the same time, Patel ordered Napster to have the system ready by that time or face a contempt of court hearing. These moves followed evidence presented by the record companies that many songs were still slipping through Napster's first few generations of filtering, prompting Patel to call Napster's previous work "disgraceful". It was after that point that Napster began complaining about micromanaging from the technical adviser. Nichols requested internal engineering documents, ordered decision-making timetables and added features to the filtering system, such as a way to monitor attempts to circumvent the filters. These might not have been bad ideas -- but it wasn't Nichols' place to be monitoring and influencing the engineering decisions, the lawyers now argue. At the end, Nichols was given complete control to certify Napster as copyright-friendly or not, the company says, but he never made his standards clear. This put the company "in the untenable position of deploying massive financial and personnel resources to a task in which [Napster] never knew what [his] goal line was," the company now charges. The Recording Industry Association of America (RIAA) could not immediately be reached for comment on Napster's latest filing. The group will file its own documents against Napster, arguing that the company should in fact be blocking all copyrighted works from unauthorised trades, in several weeks. Napster does cite the RIAA's attorneys as expressing concerns about Patel's delegation of authority to Nichols, however. "I'm not sure you can [delegate this much power], under federal rules and under the cases that I've read," RIAA attorney Russell Frackman told Patel, according to transcripts cited by Napster. "But I don't think we need to get into that. But I do have a concern that that delegation, whether or not it's legally permissible, it isn't going to work." Whatever the outcome of the appeal, Napster's own future is on shaky ground. The company has shut down its file-swapping capabilities since early July, and most of its onetime millions of users have now gone to alternatives like Music City's Morpheus or Audiogalaxy. Napster is planning to restart file-swapping and briefly restarted downloads on Wednesday night. But the company has given no date for this resurgence. The subscription service, which is expected to cost about $5 a month, is slated to launch later this summer. See the MP3 News Section for the latest headlines. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the Napster Debate. Let the editors know what you think in the Mailroom. And read other letters.