In "Contacts" panel, if I click on a MSN Messenger contact, a new chat window for that contact appears. However, if I click on a facebook or gtalk contact, the window appears only with some contacts, but not with all of them. I tried to find a difference between those who "work" and those who "don't work", but couldn't find any. Reproducible: Always
Could you send us a screenshot of the contacts panel when it doesn't work. Also run ktp-debugger from the command line and send output from the "mission-control" tab.
Created attachment 77967 [details] Screenshot This is the screen-shot you asked. I censored my contacts for privacy reasons :) It looks perfectly normal, though..
Also, I can't find the ktp-debugger in pacman or aur. Perhaps I have it already but I don't know how to launch it :(
ktp-debugger is part of ktp-common-internals since 0.5.2. However you are using Lancelot and this is unfortunately not developed by us. Reassigning to Plasma.
This part of Lancelot is officially unmaintained since it depends on Kopete which is being abandoned.