Define "doesn't work". To quote everyone's favorite infobot:

Look buddy, doesn't work is a strong statement. Does it sit on the couch all day? Is it making faces at you? Does it want more money? Please be specific!

Basically, what is it doing? Are you getting an error message? If you're just getting a Server Error, examine the error logs. Check the $response for an error condition and have it explain what went wrong. In other words, do some very basic debugging.