ListGridRecord.setIsSeparator(true), does that work?

I’m trying to have a separator node in a TreeGrid and stumbled across the above methode. However, it doesn’t show what I would expect from the docs, ie no icon and a horizontal line. But it shows the default icon and a “line” of about 2 pixels (see attachment).

Is there anything else I need to set for this to work?

I’m using GWT 2.3 and SmartGWT 2.5

TreeNodeSeparator.gif