To be sure your php.ini is being read by PHP, make a call to phpinfo(). Near the top, there will be a listing called Configuration File (php.ini). This will tell you where PHP is looking for php.ini and whether or not it's being read. If just a directory PATH exists, then it's not being read, and you should put your php.ini in that directory. If php.ini is included within the PATH, it is being read.
If php.ini is being read and you're running PHP as a module, then be sure to restart your web server after making changes to php.ini
Posted in: PHP