When the model of a combobox is modified, its comboitems are sometimes (not always, but almost always) copied outside of it.
I already posted a question in the forum (see this thread: http://forum.zkoss.org/question/98757/why-are-my-comboitems-outside-of-their-combobox) but I didn't get an answer.
I was able to create a working test case, see attachments.
In the example code, I clear the list then refill it. I also tried to instantiate a new one then call the setter. The bug occurs in both cases.