Fatal error: Call to undefined function curl_init() in,该如何解决

Fatal error: Call to undefined function curl_init() in
Fatal error: Call to undefined function curl_init() in F:\soft\phproot\index.php on line 9

用的IIS+php5.2.5

php_curl.dll 已经在到php安装目录下的ext下，
libeay32.dll和ssleay32.dll已经在php安装目录下。
已经开启extension=php_curl.dll

求解!!!!!!!!!!!!

------解决方案--------------------
extension_dir = "D:/php/ext"