The appeal lost by Microsoft in a Washington Federal Court represents the latest episode of a lawsuit that started over a year ago. Carlos Armando Amado, a Guatemalan inventor, has sued Microsoft over the method in which two of the company's software products, Access and Excel, interact with each other, accusing it of infringing on his patented technology.

The plaintiff has patented the technology that allows Access database to link directly with an Excel spreadsheet in 1990. He then tried to sell his solution to Microsoft but faced the Redmond's Company disinterest in the matter. Thereafter Microsoft used a similar solution in all released versions of Access. Initially an Orange County Judge awarded Amado with $6.1 million in damages, but both parts appealed the decision, Amado seeking no less than 500 million dollars.

Last week the United States Court of Appeals for the Federal Circuit in Washington affirmed the initial verdict. Microsoft faces now the possibility that it will have to pay Amado a percentage out of an escrow account that has built up to 65 million dollars. The actual amount of the damages will be decided in inferior court but it will take into account that Microsoft has continued to infringe upon Amado's intellectual property.