I\'ve stumbled on an issue with Comboboxes in javafx2.2. This is the scenario:
I had the same problem with a ComboBox. The buttonCell of the ComboBox is not updated correctly when I change the items of the ComboBox. This looks like a graphics bug.
I use direct manipulation of buttonCell field in ComboBox.
combo.getButtonCell().setText("");
combo.getButtonCell().setItem(null);
This is the best solution I've found without recreate the ComboBox.