Rob, they are aware of the Dropbox issue, and hopefully working on it.  Other things are failing too. 

The thought in some quarters is that it's an issue with the internet backbone, which is provided by CenturlyLink,and may be affecting the pathways between our individual user sites and the HN servers.  It's really not on your side, and there's really nothing you can do at the  moment.  Several of us are experiencing the same issues and have provided HN with a list of the sites that aren't working for us. 

*I am not a Hughesnet employee or representative. This is a customer-to-customer tech support community, and I am a customer.