CasperJS is not clicking my XPath item

Question

casper.then(function() {
    console.log("Click Change Password");
    casper.click(x('//*[@id="mainMenu"]/div[1]/ul/li[1]/a'));
});

I know it's the correct XPath. I downloaded Chrome's XPath plugin and verified that it is the correct Xpath

My console says

CasperError: Cannot dispatch mousedown event on nonexistent selector: xpath sele ctor: //*[@id="mainMenu"]/div[1]/ul/li[1]/a
C:/CasperJS/modules/casper.js:1355 in mouseEvent
C:/CasperJS/modules/casper.js:462 in click G:/Projects/index.js:137 C:/CasperJS/modules/casper.js:1553 in runStep
C:/CasperJS/modules/casper.js:399 in checkStep

Any help would be greatly appreciated

HTML From First Page

<input alt="Select" class="image  selectIcon"   name="SUBMIT-chn:$INTERNAL_password.pss"  src="docs/pics/select.png"  title="Select"   type="image"  />

HTML From Second Page (i need to enter data into the password field then click the submit button)

<input class="password text "  maxlength="250" name="_MYPW"    type="password"  />
<input  class="submit "   name="SUBMIT-VERIFY.x"       type="submit" value="Verify password" />

HTML From 3rd Page (I need to click the A HREF). [My CasperJS code above was suppose to execute Page 3. but it looks like I never navigated to this page]

<a   href="pss.exe?TRANSACTION=CGI_JUMP&SESSDATA=random&SKIN=default&LANG=en-US"        >
  Change passwords
</a>