This is a warning as well as a hint. Control-clicking on a file or folder brings up a contextual menu that includes the option to Create archive of "xxx". The created archive file is a zip file that can be unzipped with /usr/bin/unzip. So, one would think that OS X is using /usr/bin/zip to create the archive. But that isn't so. It seems that OS X creates the zip file using code internal to Finder. It seems (from output of ps or top) not to be using /usr/bin/zip. Now the warning: /usr/bin/zip is broken on HFS+ file systems. It is broken in two ways:
$ /usr/bin/tar cjvf foo.tbz foo
And to restore it, one can do:
/usr/bin/tar xjvf foo.tbz
This seems to preserve the resource forks correctly. For other methods, maybe see the hint Easily create HFS-aware PKZIP and unix archives.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20061128120143184