gwt visualization api labels disappear when displaying multiple charts - gwt

Question

I just want to display several Charts in the same Panel. It doesn't matter which chart types I use (Column, Line, Pie etc). The result is that only the first chart has labels, no matter how many charts I try to display. See this screen shot:
On the second chart, the x- and y-axis labels are missing as well as the labels for the data sets. I tested in Chrome, Firefox and IE. Always the same.
Here is the code I use:
VerticalPanel panel=new VerticalPanel();
final int height = 400;
final int width = 1200;
Date d = new Date();
//message data
final DataTable msgData = DataTable.create();
msgData.addColumn(ColumnType.DATE, "date");
msgData.addColumn(ColumnType.NUMBER, "data one");
msgData.addColumn(ColumnType.NUMBER, "data two");
msgData.addRows(6);
for (int i = 0; i < 6; i++)
{
d.setTime(d.getTime() + (1000 * 60 * 60 * 24));
msgData.setValue(i, 0, d);
msgData.setValue(i, 1, i + 11);
msgData.setValue(i, 2, i + 12);
}
final Options options = Options.create();
options.setWidth(width);
options.setHeight(height);
options.setIsStacked(true);
options.setTitle("Chart One");
panel.add(new ColumnChart(msgData, options));
d = new Date();
//new data
final DataTable newData = DataTable.create();
newData.addColumn(ColumnType.DATE, "date");
newData.addColumn(ColumnType.NUMBER, "data three");
newData.addColumn(ColumnType.NUMBER, "data four");
newData.addRows(5);
for (int i = 0; i < 5; i++)
{
d.setTime(d.getTime() + (1000 * 60 * 60 * 24));
newData.setValue(i, 0, d);
newData.setValue(i, 1, i + 3);
newData.setValue(i, 2, i + 4);
}
final Options options_new = Options.create();
options_new.setWidth(width);
options_new.setHeight(height);
options_new.setIsStacked(true);
options_new.setTitle("Chart two");
panel.add(new ColumnChart(newData, options_new));
I checked the generated html with firebug. The charts are rendered using SVG and in the second chart there are just no svg-tags for the labels, while they exist in the first chart. So the missing labels are not cut off or hidden, but are not even created.
Thanks for your help