The elections chief of a key South Florida county has resigned amid revelations of voting problems in six elections.

Miami-Dade (search) Elections Supervisor Constance Kaplan (search) resigned Thursday. Her chief deputy, Lester Sola, will take over temporarily.

The veteran Chicago election official came on board in Miami in June 2003 to fix problems from the 2000 presidential election. The county was heavily criticized after 28,000 mostly punchcard ballots (search) went uncounted. President Bush won the state — and thus the presidency — by 537 votes.

County Manager George Burgess said he questioned Kaplan about a special election on slot machines in which there were a high number of ballots with no recorded votes — known as undervotes (search).

Kaplan blamed a software fluke, he said.

Officials later identified elections in West Miami, Bay Harbor Island, Surfside, Golden Beach and Cutler Ridge with high undervotes.

Kaplan said the uncounted votes would not have changed any results, but pari-mutuel industry officials — who lost a bid to install slot machines at tracks and jai alai frontons — have asked for a new election.

Burgess said Kaplan's explanations for the problems were inadequate.