wxMaxima: how to get a new line using printf?

The documentation for printf lists

   ~%       new line
   ~&       fresh line

however, I get the following in wxMaxima:

printf(false, "line one ~% line two");
   > line one  line two

printf(false, "line one ~& line two");
   > line one  line two

I've tried a few different experiments, but can't seem to find anything that actually returns something on a new line. Any ideas? Have I missed something obvious?