Assets.loadSound does not cache Sound?

I am moving from embedded assets to dynamically loaded assets: loadBitmapData works ok, but loadSound and loadMusic seem to behave in the wrong way.

In openfl.Assets.hx loadSound and loadMusic are identical (I wonder what the difference is…), but getSound and getMusic seem pretty different.

getMusic return the requested Sound correctly and it plays ok, while getSound tells me the requested resource exists but I can’t use it asynchronously, as if the loadSound didn’t do what it should have done, caching the requested resource.
It really looks like a bug, and there is also a different behaviour between Flash and HTML5: in Flash it behaves as I said, while in HTML5 it works correctly (even if I think I haven’t heard all the requested sounds…).