I guess I figured out the problem.
In all the OS's I have set the locale to Turkish. This time I set everything to English and it works.
In windows 7, I found out that in Region and Language Settings, only Format must be in English. All other settings (Location, Keyboard, Language and System Locale) can be set to Tukish.
Using Format settings created problems in date, currency but at least PST Importer works as expected.
This solves
Zimbra Desktop Startup bug as well.
Filing a bug report.
itmltd.