The Summit of the Americas gathering of the Western Hemisphere's leaders here was supposed to be notable for the gradually improving relations between the United States and Cuba.
But détente or no, the bitter differences that continue to divide Cubans have overshadowed any goodwill.
Cuban adversaries have literally come to blows over each others' presence in the summit's parallel meetings dealing with democracy, human rights and other social issues.
The so-called civil society conferences are ending quite uncivilly.
At odds are an official delegation of Cuban "civil society," or nongovernmental groups -- although most seem to be from the very governmental Communist Party -- and a collection of dissidents from Cuba and abroad who vehemently oppose the government of Raul Castro and his brother Fidel before him.
On Wednesday, the first day of the parallel summit, members of the official delegation complained that they had not all received the credentials necessary to enter the meeting. They protested outside the hotel where the meeting was to take place, blocked the entrances and then started accusing the dissident group of being "mercenaries" and "murderers" on the payroll of the U.S. government.
"Viva Raul!" "Long live Fidel!" they shouted before the television cameras. Then they complained that the dissidents should not be allowed to participate in the conference at all. At one point, the two groups began to scuffle, with fists thrown and police called. Twelve people were arrested.
That was not the end of it. On Thursday, members of the official delegation attending the meetings attempted to derail conversation to support issues important to the Cuban government, according to participants.
"We are tired of the ... Cubans," said Sofia Montenegro, a Nicaraguan activist who was also participating. "They want to sabotage everything."
Eventually, she said, participants sneaked away from the rooms where the conference was taking place, leaving the Cubans behind. Only then, she said, could they agree on various points on the agenda, including the demand that the Organization of American States, a sponsor of the summit, create a mechanism for monitoring democratic progress in Latin American nations.
"We didn't tell them where we were going," Montenegro said of the Cubans. "We weren't going to play along anymore. We left them by themselves."
The Cuban brouhaha robbed the parallel summit of what could have been an important representation of demands from nongovernmental groups that work in the trenches of Latin American societies, participants said.
The conflict was "unfortunate," Panamanian Vice president Isabel Malo de Alvarado said, calling on the parties to "listen to each other within the frame of respect."
But the Cubans were having none of that, apparently.
Abel Prieto, a close advisor to Raul Castro, Cuba's president, and head of the Cuban delegation, said the dissident group had no standing and should never have been included in summit events.
"It's not possible to ask Cuba to dialogue with puppets of these special services agencies in the U.S.," he told El Nuevo Herald. "We can't legitimize that opposition which is absolutely fabricated; it doesn't have any weight, it doesn't have any real connection to our society."
Elizardo Sanchez, a leading human rights activist in Cuba not recognized by the government, said the important thing in Panama was being able to sit at the table. Even though that table had to be moved away from the other Cubans here.