Weird behaviour with fieldgroup and combobox


I am using vaadin version 7.5.1 and I get som weird behaviour with the Combox together with the fieldgroup.

What I do is something that I have done a lot of times. Just create a combobox with some values, set NullSelectionAllowed to true and set a default value (with select). This usually works like a charm, but this time I use a beanfieldgroup… so basically I just add:

fieldGroup.bind(comboBox, “the value in the bean”);

And it seems to work fine but in some weird way it seems that the selection is not valid since if I now expand the combobox and then click somewhere else (that is, dont choose anything in the combobox) then there is no value chosen in the combobox… (even if I NullSelectionAllowed is set to true). Also, when the combobox is expanded then the selection is on the first value…even if the text in the combobox comes from the 3rd value or something.

please help me…I have banged my head against the wall a bit with this one.