Microsoft's lawsuit against Immersion Corp., the company responsible for the "rumble" touch-feedback technology used in video-game controllers, has provided an interesting glimpse of some behind-the-scenes corporate maneuvering in the Microsoft-Sony console rivalry. And there's a new development to report: A federal judge has denied Microsoft's motion to disqualify one of the firms representing Immersion in the case.

The background: Immersion sued both Microsoft and Sony for patent infringement in 2002. A year later, Microsoft paid Immersion $26 million to settle its portion of the case. At the same time, according to Microsoft's current suit, the Redmond company negotiated rights to a payment from Immersion if it ultimately settled with Sony, as well. In the meantime, as documented in this previous post, the settlement provided Immersion with a significant amount of money at a time when it needed to fund its continued suit against Microsoft's competitor.

The current suit: Last year, Sony and Immersion announced that they had concluded their litigation and entered into a separate business agreement, including a payment to Immersion from Sony. But they didn't describe it as a settlement. Microsoft filed suit, alleging that the deal was, effectively, a settlement, and that Immersion wasn't living up to its promise of payment under their earlier agreement.

The news: As explained in U.S. District Judge Ricardo Martinez's Friday ruling (PDF, 5 pages), Microsoft had sought to disqualify the law firm of Irell & Manella, and one of its lawyers, from the case because the firm helped to draft the disputed agreement between Sony and Immersion. Microsoft based its motion on a law that prevents a lawyer from acting "as an advocate at a trial" if the lawyer is deemed a material witness.

Martinez wrote that Microsoft "failed to present sufficient evidence to show that each and every attorney at Irell & Manella are necessary witnesses to the instant litigation. Specifically, Microsoft makes no showing that every attorney at Irell & Manella will give evidence material to the determination of the issues being litigated. Microsoft merely states that all the attorneys should be disqualified by virtue of their representation of Immersion in the underlying lawsuit against Sony. Such bald assertions are insufficient in the context of a motion to disqualify."

He also cited the "at trial" language in the law: "Trial is not set until October 14, 2008. Thus, disqualification of any attorney at Irell & Manella is premature. But if it becomes likely that the attorneys at Irell & Manella are necessary witnesses after the conclusion of discovery, or on the eve of trial, Microsoft is free to move the Court for disqualification at that time."

From the archives: Microsoft sues Immersion over Sony agreement.