странная работа с сессиями в MODX revo

[[!FormIt? 
&hooks=`spam,email,redirect` 
&emailTpl=`email_tpl` 
&emailTo=`v.kamuz@gmail.com` 
&emailSubject=`Письмо с сайта [[++site_url]]` 
&sessionVars='RealCaptcha' 
&redirectTo=`25` 
&validate=`captcha:RealCaptchaValid,name:required,email:email:required,text:required:stripTags,phone:required` 
&customValidators=`RealCaptchaValid` ]] 
[[!+fi.error.captcha]]
<form class="form" action="[[~[[*id]]]]" method="post">


<input type="hidden" name="nospam:blank" value="" /> 
<label for="name">Ваше имя <span class="required">*</span>:</label> 
<span class="error">[[!+fi.error.name]]</span> 
<input id="name" type="text" name="name" value="[[!+fi.name]]" /> 
<label for="email">Телефон <span class="required">*</span>:</label> 
<span class="error">[[!+fi.error.phone]]</span> 
<input id="phone" type="text" name="phone" value="[[!+fi.phone]]" /> 
<label for="email">Email <span class="required">*</span>:</label> 
<span class="error">[[!+fi.error.email]]</span> 
<input id="email" type="text" name="email" value="[[!+fi.email]]" /> 
<label for="text">Сообщение <span class="required">*</span>:</label> 
<span class="error">[[!+fi.error.text]]</span> 
<textarea id="text" name="text" rows="7" cols="55">[[!+fi.text]]</textarea>
 [[$RealCaptcha]] 
 <input class="submit_button" type="submit" value="Отправить" />
  </form>

$_SESSION['RealCaptcha'] = md5('realadmin.ru'.$captcha->getKeyString().'realadmin.ru');