First mentioned here, my Feisty instability problems haven’t abated. The frequency has decreased to be replaced with less recoverable issues.

Today I experienced something that appeared to be suspiciously similar to this problem (missing window frames, which makes things surprisingly unuseable), but couldn’t google a solution. In the end, I removed my .kde directory (and .kderc file), restarted and things started to look a little better. The only negative was the need to reconfigure all my kde settings.