I have a vf page where i have few columns and i have used inline editing for the columns, the code is as follows:

 

    <apex:commandButton value="Add Session" action="{!createNewSession}" id="btnAddSession"/>
    <apex:commandButton value="Save" action="{!save}" id="btnSave" style="display:none"/>
    <apex:commandButton value="Cancel" action="{!cancel}" id="btnCancel" style="display:none" reRender="PanelId"/>
    <apex:pageBlockTable value="{!lstSessions}" var="Session" rendered="{!lstSessions.size>0}" id="pbt">
     <apex:column headerValue="{!$ObjectType.Session__c.Fields.Session_Status__c.Label}">
     <apex:outputField value="{!Session.Session_Status__c}"/>
     </apex:column>
     <apex:column headerValue="{!$ObjectType.Session__c.Fields.GL_Department__c.Label}">
     <apex:outputField value="{!Session.GL_Department__c}"/>
     </apex:column>
      <apex:column headerValue="{!$ObjectType.Session__c.Fields.Quantity__c.Label}">
     <apex:actionRegion >
     <table border="0" id="table_quantity">
       <tr>
        <td border="0">
          <apex:outputField value="{!Session.Quantity__c}">    <apex:inlineEditSupport event="ondblClick" showOnEdit="btnSave,btnCancel" hideOnEdit="btnAddSession" rendered="{!Session.Session_Status__c != 'Booked'}"/>                                </apex:outputField>
       </td>
       </tr>
       </table>
     </apex:actionRegion>
     </apex:column>
                  
     <apex:column headerValue="{!$ObjectType.Session__c.Fields.Unit_Cost__c.Label}">
    <apex:actionRegion >
      <table border="0" id="table_unit_cost">
      <tr>
     <td border="0">
     <apex:outputField value="{!Session.Unit_Cost__c}">                                     <apex:inlineEditSupport event="ondblClick" showOnEdit="btnSave,btnCancel" hideOnEdit="btnAddSession" rendered="{!Session.Session_Status__c != 'Booked'}"/>
     </apex:outputField>
         </td>
       </tr>
      </table>
      </apex:actionRegion>
     </apex:column>                
    </apex: pageBlockTable>

The inline editing is not consistent it is working for the first column, but it is not working for the first record in the second column, but it is working for all the remaining records in the second column.

Please reply,
Thanks in advance.