Version: 2.4.2 (using 4.4.2 (KDE 4.4.2), Kubuntu packages) Compiler: cc OS: Linux (x86_64) release 2.6.32-21-generic Line scrolling often breaks in Konsole. As a result, (1) Konsole thinks that the terminal window is smaller than it actually is and uses the upper part of the window only, and (2) when the cursor is at the bottom of the windows, all further output is printed in the last line of the terminal window, and previous lines are not scrolled up. To reproduce, create a Konsole window of 80x40 chars and have that restored at login (this step seems important). Output some longer text file, e.g., the output of dmesg will do. Note that Konsole still works as expected. Now start aptitude, or start vi. From now on, the behavior is broken. Note that I couldn't reproduce this behavior with a newly opened Konsole window, so I suspect that session management is somehow involved. Resizing the window and/or showing/disabling the menu bar also seems to fix the issue. Bug 220050 seems to related, if not the same.
The root cause should be that 80x40 initial size. See comment #21 of bug #176902 *** This bug has been marked as a duplicate of bug 176902 ***