Events don't shoot VisualForce

On the next page, Topic__c is a single-choice picklist. My intention is to manage this list which of the input fields is available below. The user selects an option and the onchange event should fire and re-receive the fields.

<apex:inputField value="{!Call_Report__c.Topic__c}" id="topic" > 
           <apex:actionSupport event="onchange" reRender="tickerInput,sectorInput,bondInput">  
             <apex:param name="topicSelection" value="{!Call_Report__c.Topic__c}" /> 
            </apex:actionSupport> 
 </apex:inputField>
<apex:inputField value="{!Call_Report__c.Tickers__c}" rendered="{!Call_Report__c.Topic__c='Issuer'}" id="tickerInput" />
<apex:inputField value="{!Call_Report__c.Sector__c}" rendered="{!Call_Report__c.Topic__c='Industry'}" id="sectorInput"/> 
<apex:inputField value="{!Call_Report__c.Security__c}" rendered="{!Call_Report__c.Topic__c='Specific Bond'}" id="bondInput" />

      

        
        
        
      

    

Am I doing something clearly wrong here? http://community.salesforce.com/t5/Visualforce-Development/Multi-select-picklist-not-firing-event-for-AJAX-refreshes/mp/173572/highlight/false#M22119 seems to imply that then what i do is reasonable ...