Version:            (using KDE 4.3.1)

This happens when you open a password-protected document, and then you realise that you don't have the password at hand right now, so you click the "Cancel" button in the window that asks for the password.
The expected behaviour would be for the password window to just dissapear and the document not be opened.

Instead, clicking Cancel causes the password window to disappear and then re-appear right away. Then clicking Cancel in that *second* password window, the window disappears again and instead brings up an error message telling you that the document can't be opened. Clicking Ok in that message box makes that go away too. Of course you're then left with an empty okular window which you'll probably want to close as well.

That's four clicks just to cancel trying to open a document. (!!!)

(Even if the "window reappering a second time" bug will be solved (1 click less), it will still be poor usability design. In fact, two more clicks could be saved if both the password entry form and the "Can't open document" message weren't shown in their own popup-windows/message boxes, but instead embedded into okular's main window area - right where the document would be shown if the correct password were entered. Handling password-protected pdf's would be even more intuitive that way, and deciding not to open a document after all after seeing the password entry from will be as simple as closing that okular window.)