title: Using mysql_real_escape_string return empty
body: <p>I use <code>mysql_real_escape_string</code> to escape <code>$this-&gt;piVars</code>.</p>
  
  <p>....de/index.php?searchGenre=5</p>
  
  <pre><code>$searchGenre = mysql_real_escape_string($this-&gt;piVars[searchGenre]);
  $result = $GLOBALS['TYPO3_DB']-&gt;exec_SELECTquery('*', 'item', 'genre = ' . $searchGenre, 'title', '');
  </code></pre>
  
  <p><code>print_r($this-&gt;piVars[searchGenre]);</code> =  string "5".</p>
  
  <p><code>var_dump($this-&gt;piVars[searchGenre]);</code> =  string(1) "9"</p>
  
  <p><code>print_r($searchGenre)</code> = empty String.</p>
  
  <p><code>var_dump($searchGenre)</code> = bool(false).</p>
  
  <p>Why?</p>