There's a bug in the Zend_Service_Rest restPost method, it doesn't set the 2nd argument for the Zend_Service_Rest _prepareRest method. This is what the original code looks like:

final public function restPost($path, $data)
{
   $this->_prepareRest($path);
   $this->_uri->queryArray($data);
   return self::getHttpClient()->post($data);
}

$this->_prepareRest($path) should actually be $this->_prepareRest($path,$data);

In the same piece of code the $this->_uri->queryArray() call causes a fatal error, because Zend_Uri_Http doesn't have such a method. It must be called with setQueryArray() and the return value should be capture in $data. Here's the correct code:

final public function restPost($path, $data)
{
   $this->_prepareRest($path);
   $data = this->_uri->setQueryArray($data);
   return self::getHttpClient()->post($data);
}

The same situation also applies for the restPut() method!!