TabPanel panel = new TabPanel();
panel.setBorders(false);
TabItem item1 = new TabItem("Hello World 1");
item1.addText("Hello...");
item1.addStyleName("pad-text");
TabItem item2 = new TabItem("Hello World 2");
item2.addText("... World!");
item2.addStyleName("pad-text");
panel.add(item1);
panel.add(item2);
The page like this:
2012-7-10 13-23-16.png2012-7-10 13-23-54.png
Why there has a line in the active TabPanel?

but when i add panel.setPlain(true);
the effect like this:
2012-7-13 11-50-39.png

Why?