Cuba and Venezuela aside, some other moments also drew criticism, such as Obama sitting through a 52-minute airing of grievances by Nicaraguan President Daniel Ortega.
"It was 50 minutes long. That's what I thought," he joked.
Some unnamed Bush advisers leaked blind quotes to some media outlets, sneering that Bush never would have sat through such a diatribe.
In another unusual incident, Bolivian President Evo Morales demanded that Obama denounce an assassination attempt on him, lest he think the United States was behind it.
When Obama held his press conference Sunday, he -- unprompted by any media questions on the subject -- denied any such act.
"I just want to be absolutely clear that I am absolutely opposed and condemn any efforts at violent overthrows of democratically elected governments -- wherever it happens in the hemisphere," Obama said. "That is not the policy of our government."
Obama's approach is markedly different than that of his predecessor, President Bush, and it remains to be seen how it plays out politically.
"Over the last few days we've seen potential positive signs in the nature of the relationship between the U.S., Cuba and Venezuela, but as I've said before, the test for all of us is not simply words but also deeds. I do believe that the signals sent so far provide at least an opportunity for frank dialogue on a range of issues, including critical areas of democracy and human rights through the hemisphere," Obama said at a news conference closing the summit.
For now, the president is back in the White House and plans to refocus his attention on the economy. He will meet with his Cabinet members today to talk about how the different agencies can cut spending.