Apache and MoinMoin are running on a machine at my employer with the hostname "daryls". (Only visible behind the firewall, of course.) So http://daryls/ goes to MyStartingPage.
When I click on HelpOnEditing and HelpOnMoinWikiSyntax while editing a page, I get a blank page. HelpContents (when I click on the HelpContents tab) is also blank.
I found a question in MoinMoin's documentation where a similar problem to mine is described. But clicking on HelpOnEditing goes to http://daryls/HelpOnEditing, HelpOnMoinWikiSyntax to http://daryls/HelpOnMoinWikiSyntax and HelpContents goes to http://daryls/HelpContents. (I don't have the extra "/instance_name/" in the URL as they describe.) But just to be sure, I cleared the contents of /usr/share/moin/data/cache, which made no difference.
I too wonder (like "twm" in the question) whether this is a configuration error. Do I need to tell MoinMoin or Apache that the domain name of the server is "daryls"?