Version:           4.3.3 (using 4.3.3 (KDE 4.3.3), Gentoo)
Compiler:          x86_64-pc-linux-gnu-gcc
OS:                Linux (x86_64) release 2.6.24-gentoo-r4

This is a 'feature' that crops up when another bug causes kontact/knode to crash. The list of news articles which have been read only seem to persisted when kontact is closed nicely. If the application isn't closed properly (i.e. it crashes), then on re-opening it displays all previously read articles as unread.

Given my usage habits Kontact is more likely to shutdown due to a crash (maybe a couple of times a month), than me logging out.

It would be nice if read status was persisted at other times (e.g., leaving a group). Possibly it is, and something else is causing articles to be marked as unread after a crash, but this seems to be the likely reason.