yepnope.js preload! prefix not working out of box

yepnope_preload_prefix_test.js

//on Chrome 12 on OSX

//after loading in vanilla yepnope js from
//https://github.com/SlexAxton/yepnope.js/blob/master/yepnope.js
//calling this results in application.js loading into an <img> tag then *executing* despite !preload prefix
yepnope("preload!/javascripts/application.js");

//on line 410 of the lib there is a resource.noexec check, but no other refs in the lib to 'noexec'
//when setting this to true, the desired load-but-dont-execute behavior works.

//likewise, rolling my own preload! prefix to set noexec...
yepnope.addPrefix("preload", function(resource) {
  resource.noexec = true;
  return resource;
});

//then executing...
yepnope("preload!/javascripts/application.js");

//also results in the desired load-but-dont-execute behavior. I'd guess the built-in prefix is supposed to do this...
//so I'm not sure where the disconnect is.

//- *RESOLUTION* - the 'built-in' prefix isn't actually in the yepnope.js download, but it is
//in the distro/github repo on /prefixes, and you'd have to add it yourself.
//sure enough the code is identical to the above.