TALLAHASSEE, Fla. — Thousands of Floridians who think they're registered to vote could be turned away at the polls Nov. 2 because their voter registration forms weren't completely filled out, officials said Friday.

Secretary of State Glenda Hood said some groups registering voters are turning in application forms with information missing, such as unchecked boxes asking whether applicants are citizens, mentally incompetent or felons.

A group that's been seeking copies of the incomplete applications in an effort to help people complete them said Hood's office, citing state law, has begun blocking them.

"Clearly, way over the number that could determine the election" won't be able to vote, said Judith Browne, a lawyer with the Washington-based Advancement Project, which promotes multiracial participation in voting. She was referring to President Bush's disputed 537-vote victory in Florida that gave him the presidency in 2000.

During that election, state and local election officials were criticized on a host of issues, from people mistakenly removed from voter rolls to the infamous "butterfly ballot" in Palm Beach County that may have led Al Gore supporters to vote for third-party candidate Pat Buchanan instead.

While the Advancement Project is not registering voters itself, it assists groups that are, including America's Families United, which tries to register voters in poor and minority communities.

America's Families United is suing the Duval County elections supervisor to get copies of 1,441 rejected applications there. Browne said a judge ruled against it Friday.

Previously, the Advancement Project received copies of forms from Miami-Dade, Orange, Hillsborough and other counties. In Miami-Dade and Broward alone, Browne said 12,000 incomplete ballots were turned in.

Acting Duval elections supervisor Richard Carlberg said his office is trying to call the 1,441 applicants to let them know they won't be able to vote unless the forms are completed, but said many of the phone numbers on the forms aren't working numbers.

Hood said her office is only trying to help elections supervisors follow the law and that incomplete forms must be rejected.

Hood recommended that people who were registered by a group instead of at their county elections office check to make sure they are actually registered.

She also said anyone registering to vote outside a county office should double check to make sure all information is accurate, forms are completely filled out and that the group plans to turn the applications in before midnight Monday.