Version:           1.0 (using KDE 4.1.1)
OS:                Linux
Installed from:    Unspecified Linux

Normally, Kontact stores its contact list like so:

~/.kde4/share/apps/kopete/contactlist.xml

<meta-contact contactId="JabberProtocol:$JABBERID$:$CQNTACTJABBERID" >
...
</meta-contact >

But, if the contact is synchronized with the addressbook (right-click on the contact in the contact list > Properties > Pick the Addressbook entry to link to), the meta-contact field gets modified to look like this:

<meta-contact contactId="RgguajxEQ1" >
...
</meta-contact >

Both (my) $JABBERID and $CQNTACTJABBERID are not present ni the heading. Hence, the contact is not shown in the Lancelot Contacts tab, even if the contact is online.

This decreases the coolness factor of Lancelot and that's not good! :)