A congressional task force called Thursday for a speedy resolution to a southwest Florida election dispute that questions the accuracy of ATM-style voting machines. Democrat Christine Jennings claims that touch-screen voting machines in Sarasota County failed to register up to 18,000 votes. Republican Vern Buchanan was declared the winner by 369 votes after two recounts and a state audit found no problems. GAO investigators will gather information on Sarasota County's voting systems, analyze the 18,000 so-called ''undervotes,'' review tests and audits done after the election and determine if more tests are needed. Jennings said Thursday the she was pleased even though the approach brings her no closer to gaining access to hardware and software that the machines' maker, Omaha, Neb.-based Election Systems & Software Inc., says is a trade secret.