Forum OpenACS Development: changing messages - how does this work, exactly?

So I went into acs-lang and added some messages, and edited a couple.  I exported from each package, so I could commit the .xml file.  Then I tried looking at a page that used one of my new messages - not found.  So I tried importing the xml file back - nope, still not found. I restarted - still not found.  What is the magic incantation I'm missing here?  TIA!