Version: SVN from second half of November or so (using KDE Devel) Installed from: Compiled sources OS: Linux I don't know what exactly Konversation does when the disk gets full, but it is not pretty. (I know it was full because I was just in the process of trying to free some space when this occurred.) It was quite strange: KWin was perfectly responsive, I could move windows around and all, but none of the actual apps themselves would even redraw themselves, they were just black boxes with a titlebar. Accompanied by a whole lot of disk activity, which may or may not have been swapping, but my bet would be not. I sat there for a while waiting for ksysguard to open so I could see what happen, until eventually I realized it's not going to, at which point I switched to a different vt and opened top -- which, again, happened without any noticeable slowdown at all. There I saw konvi using 100% CPU, killed it, switched back to X, and everything was perfect again. This is just speculation, but I suspect it may have to do with logging.
Considering this only happened when your disk got full, i see no need for further investigation; a full disk could trigger all sort of weird behaviour.
I'm going to be evil here and close this as WORKSFORME as I've had Konversation running with logging turned on while my disk got filled up to 100% about half a dozen times over the last year, and never had a problem. If there was one, it's apparently fixed.