Could you try to disable all other plugins, one at a time, to make sure that no other plugins conflict with Jetpack? I noticed that you use the Infinite Scroll plugin, as well as other plugins that may change the theme's UI, like WP UI. You might want to start by deactivating these 2 plugins.
Let me know if you find a conflicting plugin!
@quapet Could you please start your own thread, as per the Forum Welcome?
You can post here:
http://wordpress.org/support/plugin/jetpack#postform
Thank you!