On custom module form submission success, index is appended to page url

Question

I have a custom module for contact us in my Magento site.

1) config.xml is like following

<?xml version="1.0"?>
---
---
---
<frontend>
    <routers>
        <requestcatalogue>
            <use>standard</use>
            <args>
                <module>Namespace_Requestcatalogue</module>
                <frontName>requestcatalogue</frontName>
            </args>
        </requestcatalogue>
    </routers>
    <layout>
        <updates>
            <requestcatalogue>
                <file>requestcatalogue.xml</file>
            </requestcatalogue>
        </updates>
    </layout>
</frontend>   
<admin>
    <routers>
        <adminhtml>
            <args>
                <modules>
                    <adminrequestcatalogue before="Mage_Adminhtml">Namespace_Requestcatalogue_Adminhtml</adminrequestcatalogue>
                </modules>
            </args>
        </adminhtml>
    </routers>
</admin>

2) There is a link in the phtml file as following

  <li class=" ">
    <a title="<?php echo $this->__('Contact Us') ?>" href="<?php echo $this->getUrl('contact') ?>"><?php echo $this->__('Contact Us') ?></a>
    </li>

3) Form action is as following

<form method="post" id="ContactusForm" action="http://localhost/mymagento/contactus/index/post/">

4) controller post action is like following

public function postAction()
{
    -----
    -----
    -----
    $this->_redirect('*/*/');  // on successful submission
    return;
    ----

5) There is a url rewrite in admin as following

My question is when I submit the form successfully the page url in the browser is appended with index.

before form submission page url

http://localhost/mymagento/contactus

after submission page url

http://localhost/mymagento/contactus/index/

How do I remove this index appended in the last from the url?

Update : Recently I applied SUPEE-6788 patch to site, before that it was working correctly.

Answer 1

Try this

4) controller post action is like following

public function postAction()
{
    -----
    -----
    -----
    $this->_redirect('contactus');  // on successful submission
    return;
    ----