A dealer in Holland that Microsoft sued in May for copyright infringement has complained to the European Commission that Microsoft charges anywhere from 30%-50% more for its software in Europe than in does in the U.S. - except for Vista, which is only 15% more.

It claims it's an antitrust violation in violation of articles 81 (anti-competitive behavior) and 82 (abuse of dominance) of the European Treaty.

Meanwhile, Microsoft is suing that dealer, Samir Abdalla, and his company, HW Trading BV, in federal court in California, saying he imports into the U.S. low-cost Microsoft Student Media intended for schools abroad and sells it illegally to unauthorized resellers.

The suit says Abdalla is "attempting to exploit the substantial difference between the retail prices of Microsoft software in the United States and the vastly reduced prices of Microsoft software licensed for educational use abroad."

The student software included at least Office 2003 Professional and Standard and XP Professional for which Abdalla allegedly collected over $3.6 million between March 2006 and May 2007.

Microsoft wants damages, a constructive trust and an injunction.