The issue when clicking image properties and browse server in CKEditor for first time, the CKFinder will popup and went behind the master/main page. Then you need to click and focus back the CKFinder windows from taskbar.
It only happen for first time clicking the browse server with new session/clear cache. Open firefox and go to http://ckeditor.com/demo. Then click the image properties and browse server. It will popup behind the main screen. After that, close the CKFinder screen and click browse server, it will popup correctly without going behind the main screen.
It only happen for first time clicking the browse server with new session/clear cache. Open firefox and go to http://ckeditor.com/demo. Then click the image properties and browse server. It will popup behind the main screen. After that, close the CKFinder screen and click browse server, it will popup correctly without going behind the main screen.

The only thing I noted is javascript console (each time I click the "browse server" button) reports:
that point to:
but I don't think it has anything to do: the error happens every click (also in WINXP), the problem only with the first (never in WINXP).
I hope someone find the cause, so #9433 can fix the problem in the next release... thanks in advance!
[edit]
The above error in javascript console doesn't happen in "-safe-mode", so I'm pretty sure that it has nothing to do with the problem.
This bug still occurs in Firefox 18.01!