Mercer County has sued UniLect Co. for $925,000, arguing that the California-based voting machine company breached a warranty agreement.

From 2001 to 2004, Mercer used UniLect's Patriot, a touch-screen machine, but it and two other counties, Beaver and Greene, were forced to acquire new machines when Pennsylvania decertified the Patriot in April of last year.

Mercer County Commissioner Brian Beader said the decertification violated the terms of a 20-year warranty on the machines.

Mercer's Patriots experienced problems during the 2004 general election. Officials incorrectly programmed the machines, and the county had a presidential undervote of greater than 7 percent.