A report on problems in Cuyahoga County, Ohio may be found here. From the press release:

A month after Election Day, filmmaker Sanford Lewis released a video report profiling the problems that numerous Cleveland area voters had casting their ballot. According to the filmmaker, voting did not go as smoothly as was commonly portrayed. Many voters faced serious problems with mail-in voting. Thirty thousand voters in just this one county cast provisional ballots that were not included in the results announced on Election Day; by the time provisional ballots were counted 10 days after Election Day, 7000 of these ballots were invalidated.