Combobox hangs if open during ajax update

[edrusiani2009]

Hi

i'm working on an application running on jboss 4.2.3 with Seam 2.1.1.GA and richfaces 3.3.2

i have a set of combobox that can update each other (for example, country and city. if you choose a country, you see a filtered list of cities, but if you choose a city, the other control shows the correct country)

the problem arises when you choose a result in a combobox and then open another one before the ajax call updates its content. The combobox usually hangs, wide open, even if you select a value. The only solution, for the user, is reloading the page. How can i prevent that?

Here's the combobox control code.

<rich:comboBox      
        id="GedTagCmb"
     value="#{attributoReg.valore}"
     suggestionValues="#{attributoReg.getCurrentSuggestItem()}"
         directInputSuggestions="true"
         width="#{attributoReg.attributoregistrazione.attributo.attribArch_UIT.getProperty('width')}"
         >
     <a4j:support event="onfocus" eventsQueue="reg">
         <f:setPropertyActionListener value="#{attributoReg}" target="#{arcRegManager.arBeanList.selectedBean}" />
     </a4j:support>
     <a4j:support actionListener="#{arcRegManager.arBeanList.onModify}" event="onchange" eventsQueue="reg"  reRender="GedTagCmb, GedTagLongTxt, GedTagTxt, GedTagNum, GedTagDate"/>
</rich:comboBox>


Thanks for all your help

Enrico