Yes, I've noticed similar behavior, except that the list-cache issue is more likely to give
me empty messages than wrong messages.
Strangely, it's a much bigger problem on one of my machines than on the other, despite
them running the same version of Kubuntu (though different kernels). I eventually got
tired of nuking the IMAP cache on the one machine, and now use KMail only on the other
Konqueror's crashes seem to be most often due to memory overload or (more rarely)
memory worse than I'd like.