Whenever konsole displays output of `ls -al` on my Gentoo box showing a broken symlink (white blinking text on a red background) in a tab running bash, it takes more than one second for the shell (in the same tab only) to register a keypress. When I type some text faster, all letters show up at the same time. Other tabs are not affected by this behavior. Speed goes back to normal as soon as the text is no longer visible in the window (either by typing `reset` to the bash prompt or simply by pressing Enter repeatedly, so that the blinking text gets scrolled up to the part of the buffer which is no longer visible. It doesn't matter that it is still accessible via moving the scrollbar.). Please let me know what kind of further information might be needed, I can also try various patches.
Created attachment 40749 [details] konsole-blink Attached is a simple text with escape sequences which cause my konsole to experience described delays. Simply `cat konsole-blink` is enough to trigger the issue on my box.
Can't reproduce this in KDE-4.7.0 on gentoo. Feel free to reopen if this still happens in recent version.