Hi! It seems that kopete - both unstable 0.7.2 and stable 0.7.1 - install into the wrong directory. Instead of going into /usr/kde/3.1/ ($KDEDIR), it installs straight into /usr. Anno.
Nope, it's correct. It's where all KDE applications go. Honest. The reasoning is that you can use it between multiple versions of KDE. It was a design decision made a long time ago, and, luckily enough, it works!