Fix Header PageblockTable Salesforce with flickering issue fix in Mozila and IE

<apex:page standardController="Account" standardStylesheets="false">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js"></script>
    <script src="{!$Resource.jqueryfixheadertable}"></script>
   <apex:stylesheet value="{!$Resource.base}" />
   <apex:stylesheet value="{!$Resource.themefile}" />
  
 <apex:form id="theform"> 

    <script>
    $(document).ready(function() {
        $('.fixme').fixheadertable({
             caption : 'My header is fixed !',
             height  : 200
        });
    });
    </script> 
  
  
   <apex:pageBlock title="My Content"  >

        <apex:pageBlockTable value="{!account.Contacts}" var="item" styleclass="fixme">
             <apex:column headerValue="Col1"   value="{!item.name}"/>
              <apex:column headerValue="Col2"   value="{!item.name}"/>
                <apex:column headerValue="Col2"   value="{!item.name}"/>
                  <apex:column headerValue="Col2"   value="{!item.name}"/> 

      </apex:pageBlockTable>

    </apex:pageBlock> </apex:form>
</apex:page>

Link to CSS and Jquery Files

1  . base.css

2 .themefile

3. jqueryfixheadertable

Press Ctrl+s to Save after clicking  on above links and store all file in static resources .

Reference :https://github.com/benjaminleouzon/tablefixedheader