I have a VF page with a pageBlockTable that has a column of checkboxes, whose header contains a checkbox as well. I want all checkboxes to have "RTL" direction. It works for the ones in the column, but not for the header. Here is a very simplified version of my page:

<apex:page controller="test">
    <apex:form >
        <apex:pageBlock >
            <apex:pageBlockTable value="{!contacts}" var="contact">
                 <apex:column width="25px" dir="RTL" headerdir="RTL">  
                     <apex:facet name="header">
                          <apex:inputCheckbox dir="RTL"/>
                      </apex:facet>
                      <apex:inputCheckbox /> 
                  </apex:column>
                  <apex:column value="{!contact.Name}"/>
               </apex:pageBlockTable>
           </apex:pageBlock>
    </apex:form>
</apex:page>

controller:

public class test
{
    public List<Contact> contacts
     {
        get
        {
            return [Select Name, Id
            From Contact];
        }
    }
}

 As you see, I tried to "push" the checkbox to the right with either headerDir attribute of the column, or dir attribute of the checkbox within the facet, but none works, the checkbox in the header stays on the left side. Any suggestions/explanations?