WordPress sporadically fails to connect to DB

I’ve installed WordPress using the DH install option on a subdomain to test it out.

It is working, but barely. Maybe times I get this error page:

"We’re having a little trouble selecting the proper database for WordPress.

Are you sure it exists?
Your database name is currently specified as [my database name]. Is this correct?
On some systems the name of your database is prefixed with your username, so it would be like username_wordpress. Could that be the problem?
WordPress Support Forums"

What’s weird is that if I hit refresh, eventually the page works. So it CAN connect to the database, but only occasionally.

Any ideas?

It sounds like either a problem with your database server, or your database. Contact DH support.