The touch-screen voting machines Katherine Harris championed as secretary of state after the 2000 presidential recount may have botched this year's election to replace her in the U.S. House, and it's likely going to mean another Florida recount. More than 18,000 Sarasota County voters who marked other races didn't have a vote register in the House race, a rate much higher than the rest of the district. The county's elections supervisor, Kathy Dent, had requested the team after one of the candidates reported complaints about voting machines malfunctioning. Earlier, Dent defended her staff and the machines, arguing that the thousands of voters must have either overlooked the race...or simply decided not to vote for either candidate in a race marked by mudslinging. But she couldn't explain why the undervote rate in her county was so much higher than in the four other counties in the district. Republican Vern Buchanan declared victory in the race with a 373-vote lead over Democrat Christine Jennings-less than 0.2 percent. Florida law requires a machine recount if the difference between the top candidates is less than half a percent. If the machine tallies find a margin of less than a quarter percent, a manual recount is conducted. To do a manual recount for touch-screens, officials go back over the images of the electronic ballots where the machine didn't register a choice. State rules essentially say that if the machine doesn't show that a voter chose a candidate, the voter is assumed to have meant to skip the race. It would be tough to prove otherwise.