First the problem was already solved, see The Halo's latest post. Second although mostly technically true, this statement isn't true in general.
All depend on the used compression algorithm and the data itself. Most time you won't end with that and only get sightly better compression, but I wouldn't general write that you can't compress a already compressed file to 41% of it size.
True, some files are able to be compressed more than others, but as we all know, extreme compression can be bad.
A funny example, mixed with a warning.
A long time ago, in an internet world that is slowly fading away, (warez forums) you could find super compressed downloads that contained the installer iso image of Windows XP that were only 14.5 mb's in size.
The actual pre compression size was about 4gb's.
The program used was KGB Archiver. <<<< EVIL PROGRAM, DO NOT USE!!!!!!!!!!!
After compression, you, the one compressing it could extract the file to test it and it would work fine, and you could install windows with the ISO you had compressed and then extracted, after burning it to disc.
Hint: The data for the compressed file was stored in your system when you compressed it, and that data was used during the test extraction.
BUT!!!!
Anyone who downloaded that compressed file got nothing but an ISO file that was full of dummy files that had file names, but contained no code at all when you examined the files with notepad ++.
The code was compressed right out of the files.
Needless to say, a lot of people got really pissed, especially when people kept sharing those crappy downloads on other sites.