A spokesman for Bowen's office could not be reached for comment Tuesday.

In a statement Monday, ES&S said that the "limited modifications made to the AutoMark's hardware were extremely minor and had nothing to do with the operation or functionality of the Voter Assist Terminal. The secretary of state's office has not disputed that fact."

The only changes made to the devices were minor engineering modifications, according to ES&S.

The company also said that the new A200 model was recertified and requalified under federal requirements through testing done by an independent testing lab. "The hardware changes were approved through the established process to review, test and qualify voting equipment at the national level," ES&S said. "As a result, the ES&S AutoMark in use across the country and in California has been tested and federally qualified for certification."

"We are reviewing the determination issued today by the California secretary of state," the company said. "Throughout this process, we have asked that the secretary of state's staff consider all relevant information, deal with each election equipment manufacturer fairly and act in the best interests of California voters. Unfortunately, the secretary's determination and the lawsuit she is filing fails to do this and may adversely affect the use of a widely acclaimed device that has allowed many California voters with disabilities to vote privately and independently for the first time."

In a statement on its Web site in August, AutoMark said that the firmware in the original A100 and revised A200 devices is exactly the same firmware that state and federal authorities previously certified. "During the manufacturing process, ATS, with the approval of the independent federal testing agency and ES&S, implemented certain engineering changes that collectively became known as 'A200' or 'Phase 2,'" the company said. "These engineering changes were nonfunctional modifications made for ease of manufacture and in no way changed the operation of the device."