van-abel on "[Plugin: Jetpack by WordPress.com] Fatal error: Call to undefined method WP_Http"

When I try to Connect to the WP.com I get:

Fatal error: Call to undefined method WP_Http::_get_first_available_transport() in ..../wp-source/wp-includes/http.php on line 223

How to fix this?

My WP version is 3.4.2.

http://wordpress.org/extend/plugins/jetpack/