It was NoScript: NoScript set to allow scripts globally and it works, set to disable scripts by default and it freezes FF.
But latency is a HUGE problem in Brazil[1], and in probably any country that's far removed from the major backbones.
Yes, I can watch Youtube just fine in Brazil but I can't tell you the number of times that Skype video or other highly interactive apps wouldn't start or conk out because of poor latency.
The public has no comprehension of latency, but it's really important that this gets factored in somehow, especially for places like Brazil that generally have poor latency.
[1] http://brazilsense.com/index.php?title=Wi-Fi_and_Internet_se...
Brazil's poor latency may be partly explained by the fact that a lot of their connections have to go through the US and Canada:
"The shape of the Internet varies considerably when examining individual regions. In Europe, the majority of cross-border capacity is between European countries, while in Latin America and the Caribbean the majority of international capacity is connected to the U.S. & Canada."[1]
"More than 80% of Africa's and Latin America's international Internet bandwidth connect to cities outside their regions. In the case of Latin America, 60% of the region's interregional capacity connects to a single city, Miami."[2]
Also, because of Brazil's distance from the economic center of the Internet, they probably don't get the advantage of unpaid peering relationships.
[1] http://www.telegeography.com/assets/website/images/maps/glob...
[2] http://www.telegeography.com/assets/website/images/maps/glob...
Why would proximity to China matter? They probably have the worst internet in Asia (outside of DPRK of course).