Version: 1.5 (using KDE 3.4.0, Debian Package 4:3.4.0-0ubuntu3 (3.1)) Compiler: gcc version 3.3.5 (Debian 1:3.3.5-8ubuntu2) OS: Linux (i686) release 2.6.10-5-386 (Edit -> Clear History) and Edit -> Clear All Histories) do not work. Even if you change permissions of the file .bash_history it still does not work. The only way you can clear the history for konsole 1.5 on KDE 3.4 is to remove/delete the file .bash_history.
Sorry, you've been misled. The Clear (All) History is to remove the buffer of lines output to Konsole, the one you can scroll on using the scrollbars. It does not and cannot affect shell history. You can re-file this as a wish, if you want.