One Laptop Per Child (OLPC), the project which aims to deliver cheap laptops to the developing world, has suffered its latest setback: a lawsuit alleging that it stole the design for the device's keyboard.

A Boston-based company has filed a claim in Nigeria - one of the countries where the laptops were due to be distributed - alleging that the OLPC has infringed a patent it holds on a 'four shift key' keyboard, which helps the computer handle multiple languages.

The company, called Lancor, owns a patent on the design in Nigeria, and reportedly wants the Federal Court in Lagos to award it "substantial damages", and to issue an injunction which would permanently prevent the OLPC from manufacturing and selling its machine, which is called the XO.

Lancor's chief executive said that he had tried to reach a settlement with the OLPC but had not got a "reasonable response" from the project. The OLPC could have "sought a licence and gotten it for a minimal fee", Ade Oyegbola told PC World. "We're hoping they can come to their senses and we can sit down and come to a reasonable settlement."

The OLPC said that it had not yet seen the legal filings, but that to its knowledge all the intellectual property used in its laptop was either owned by OLPC or properly licensed. "We have the utmost respect for intellectual property owners," Robert Fadel , OLPC's director of finance and operations, was quoted as saying.

The development is the latest in a string of setbacks for the two-year-old project, which aims to bridge the world's 'digital divide' by bringing cheap laptops to the estimated five billion people who do not have access to a computer.

In recent months, the initial cost of OLPC's machines has risen to $188, and there has also been fierce competition from makers of rival machines, as well as fears that support from governments in developing countries was wavering.

Earlier this week a Nigerian education minister questioned a decision by the previous Government to order one million of the OLPC's machines, saying it was more important for students to have access to basic facilities like classrooms and uniforms than cheap computers.

Walter Bender, head of software development at OLPC, told the BBC that politicians had been unwilling to commit to buying the machines because "change equals risk," but that leaders in such countries needed to be "bold" and that changes in education would not happen in "small, incremental steps."

Some of the big names from the computing industry - whose parts were not included in the XO - have also criticised the machine itself, which has a special screen that can be easily seen outdoors, and a wind-up crank which means it does not need mains power.

Craig Barrett, the chairman of Intel, whose main rival, AMD, is suppling the processors used in the XO, said it would be "more realistic" to call the XO a "$100 gadget" than a $100 laptop.

Intel is in turn launching its own low-cost laptop, the Classmate, a move which OLPC's founder, Nicholas Negroponte, said was deliberately designed to underprice and undermine his own project.

Bill Gates, the chairman of Microsoft and one of the world's biggest philanthopists, meanwhile said that buyers should "get a decent computer" rather than opt for the OLPC's machine.

OLPC recently announced that it had begun "mass production" of the machines, and said it had received its first order for 100,000 laptops - from the government of Uruguay. A deal with Peru was also "very, very close", a spokesman said.

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