Certain plugins aren't udpate

Hi, I'm having troubles with some of my plugins not updating automatically. maloneconsultantsgroup.com has 3 plugins (Jetpack, MailChimp for WordPress and ManageWP) that consistently fail to update. Additionally, the GravityForms MailChimp Add-On seems to not update consistently either. Can you give me any more information why certain sites or plugins don't seem to update and what I can do to keep the up to date?

Thanks,

Collin Condray

Director of Technology

BlueZooCreative.com