My site has been having the same problem (I think). Occasionally I just can't connect to mysubdomain.heliohost.org OR heliohost.org, but then it works again 5-10 minutes later.
I use Drupal (a CMS) on my site, and have 'ran cron' before - I think it checks for updates to Drupal. I don't really know what cron does, but could it be causing my problem?