Okular for Windows and for Mac OS aren't considered stable as of now. Unfortunately the link in the homepage: http://pdfreaders.org/ brings the users directly to the download page where there is no mention to the fact that the software is not ready for day to day use. http://windows.kde.org/download.php The advise: "KDE on Windows is not in the final state, so applications can be unsuitable for day to day use yet." is present only in the homepage: http://windows.kde.org/
Probably it's better to put an additional footnote to warn the users.
Regards, Diego