The method listed in the OP worked for me as well. Actually, it didn't work in the beginning. I had to add one more ingredient to the mix, ie., "suPHP_ConfigPath /path/to/php.ini" in my .htaccess file to specify where the php.ini file is since my host hadn't configured a specific path for it (or maybe configured one that i dont know about).
You might want to add it in the OP.