The long-running Linux patent dispute between The SCO Group and IBM took another twist last week when IBM filed court documents that suggest Microsoft agreed to back up BayStar Capital\u2019s investment in SCO.Executives from BayStar, an investment company, have said previously that Microsoft introduced BayStar to SCO. In a declaration filed last week with the U.S. District Court for the District of Utah, a BayStar executive said Microsoft\u2019s involvement went further than that.Microsoft\u2019s senior vice president of corporate development and strategy promised that Microsoft would "guarantee" BayStar\u2019s part in a $50 million investment in SCO, according to the declaration from BayStar managing member Larry Goldfarb.After BayStar made the investment, however, Microsoft stopped returning the company\u2019s phone calls and the Microsoft executive who made the promise, named in the filing only as Mr. Emerson, was likely fired, according to Goldfarb. BayStar ultimately sold its investment back to SCO at a loss. The investment company blamed SCO\u2019s high cash burn rate and the questionable viability of its products for its decision to sell, Goldfarb said.Microsoft did not immediately respond to a request for comment Monday. In a report in the online edition of The Wall Street Journal, a Microsoft spokesman said it never made any such guarantee to BayStar.Microsoft has been scrutinized for any sign of involvement in BayStar\u2019s investment. Such a move would suggest that Microsoft helped support SCO\u2019s lawsuit against IBM as a way to hamper the growth of Linux, which presented a threat to Microsoft\u2019s own business.If Microsoft did make such an offer to BayStar, it would have been a very risky move, one industry analyst said."Given the enormous scrutiny that Microsoft is under, I think it\u2019s extremely unlikely that they would have engaged in any kind of conspiracy because the potential upside simply isn\u2019t great enough and the potential downside is great," said Gary Barnett, an analyst with Ovum. The battle between IBM and SCO started in 2003 when SCO charged IBM with offering open-source software based on source code that SCO claimed to own. The company then threatened to sue businesses using Linux for patent infringement. In July of this year, a judge dismissed nearly 200 SCO claims, saying the company didn\u2019t offer enough detail of the alleged patent infringements. A PDF of last week\u2019s filing is posted on the Groklaw website.-Nancy Gohring, IDG News Service (Dublin Bureau)Related Links:\n\nThe SCO Slugfest\n\nSCO vs. IBM: The Plaintiff RepliesCheck out our CIO News Alerts and Tech Informer pages for more updated news coverage.