There is (was - not sure if fixed now) a bug with Mac OS X as well. If the destination for the unstuffed archive has 'show folder info' enabled, then this can also create an empty folder.
A practical example of this is if you are creating the unstuffed folder on (in) the desktop and you have the volume information showing, such as in the attached thumbnail - which is when I encountered the problem. I found the workaround on the Allume website, which insisted it had posted bug reports with Apple at intervals for over a year, without any fix.