Upong Magento 1.4 they introduced something very usefull for Develoment/Production management, enabling/disabling Development Mode trhough htaccess.
This way you can have a .htaccess in your development root dir tailored for development and another (or none) in the production environment.
In /index.php change your code to:
if (isset($_SERVER['MAGE_IS_DEVELOPER_MODE'])) {
print_r(”Dev Mode”);
Mage::setIsDeveloperMode(true);
ini_set(’display_errors’, 1);
}
and in your /.htaccess add this line to the end of the file
#Magento Developer Mode
SetEnv MAGE_IS_DEVELOPER_MODE "true"
Change from “true” to “false” according your needs.