Update.
I've installed KE 4.3.1 and that error message mentioned in the first post in this thread is gone. Now everytime Kopete starts up I get a message that two users, one on Yahoo and the other on Hotmail have added me to their contact list I'm given the choice to "Authorise" or "Block." This happens for the same two users, each and very time Kopete is started. I've talked to them and they are not repeatedly "authorizing" me. The problem is on the Kopete side.

Kopete in KDE 3.5.10 could not remember notificiations for users (sounds)
and that seems to be repaired in the version that is included with KDE 4.3.1, but now it can't remember the "Sleathed" settings. Sigh.. Seems as one thing gets fixed another gets broken.

Hello,

Anyone interested in this backported patch for 3.5.10 ?

http://launchpadlibrarian.net/33036596/kopete_yahoo_update_login.patch

D.