Да, у меня денвер. Тестирую на компе.
<!--error--><br />
<b>Warning</b>: filter_var_array() expects parameter 1 to be array, string given in <b>Z:\home\19sp.ru\www\forum\mysp\adm\include\uplo ad_photo\ajax_upload.php</b> on line <b>156</b><br />
<script language=JavaScript src='/denwer/errors/phperror_js.php'></script><!--error--><br />
<b>Warning</b>: array_diff() [<a href='function.array-diff'>function.array-diff</a>]: Argument #1 is not an array in <b>Z:\home\19sp.ru\www\forum\mysp\adm\include\uplo ad_photo\ajax_upload.php</b> on line <b>156</b><br />
<script language=JavaScript src='/denwer/errors/phperror_js.php'></script>
В этой же строке:
if($url = array_diff(filter_var_array($_POST['file_url'], FILTER_VALIDATE_URL), array(false)))