Netfirms hosted WP site often fails to open page

I am new to WP. I got a good deal with Netfirms for a year of hosting. However, I find that I frequently get a “Failed to open page” error that says it can’t connect to the server ‘mikezupan.com’.

I get this error with the admin and end-user pages of my site periodically, but then it clears up and loads fine. The pages also sometimes take a while to load as the browser shows a ‘contacting’ status.

Netfirms hosts my site and they are the registrar for my domains.

Is this a common problem with Netfirms hosting, or is it a domain registrar issue? Or is it something completely different?

I’m fairly new to all this, so I’m not quite sure what this is a symptom of.