I broke down and used a regular expression to convert double quotes to single quotes, and the problem went away on Safari/Firefox (using FusionCharts.js version 1.2.1.beta).
It would be nice to fix this problem for all browsers. It just doesn't seem right to have to convert perfectly valid XML into something else
Thanks!
Sunil
myChart.setDataXML('<chart caption=\'Monthly Sales Summary\' ><set label=\'January\' value=\'1740\' /><set label=\'February\' value=\'19800\' /></chart>');
myChart.setDataXML('<chart caption="Monthly Sales Summary" ><set label="January" value="1740" /><set label="February" value="19800" /></chart>');
myChart.setDataXML("<chart caption=\"Monthly Sales Summary\" ><set label=\"January\" value=\"1740\" /><set label=\"February\" value=\"19800\" /></chart>");