Unable to install jetpack

Every time I’ve updated jetpack recently, it’s then stopped working and I’ve had to reinstall it. Now, however, every time I go to install it, I get the following error message:

The webpage at http://52ndcentury.com/wordpress/wp-admin/update.php?action=install-plugin&plugin=jetpack&_wpnonce=a3718a1b2a might be temporarily down or it may have moved permanently to a new web address.

This doesn’t seem to happen when trying to install any other plugin.

I’ve also tried downloading the files manually and putting them into my plugin folder, but it is not showing up on my list of available plugins on my dashboard.

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