Safari interface annoyances

One of Safari's more annoying user-interface decisions is the "Safari can't find server" error message.

If you open a link in a new page or a new tab and encounter this error, when you switch to the page or tab in question, you cannot close or refresh the page or tab until you dismiss the error message. This is simply terrible interface design, and not worthy of Apple. Whoever is responsible for Safari's UI, please do something about this! The error message should appear in the title bar, or address bar, or simply as a webpage saying "Server not found", not as a drop-down sheet that has to be dismissed.