Download report split between mysite.com and www.mysite.com

In trying to get (manually-entered from nginx logs) direct downloads to appear in my Downloads report, I noticed that while most downloads are listed under “mysite.com”, many are also displayed under “www.mysite.com”. Is there any way to configure Piwik to merge those together? In defining the site, it says that the “www” version is automatically combined along with the non-www leading URL, but that doesn’t seem to be happening here.

Was this a problem with my import (should I have explicitly told it “hostname=www.mysite.com” or some such?)