I don't see any "plugins" listed in the "plugins" page in the configuration dialog?
There are two solutions to this problem. If you used binary packages, then make sure that you used binary packages designed for your distribution, and the specific version of your distribution. Crossing distributions and versions around will not work with Kopete. If there are no binary packages for your system, you must compile Kopete using the source packages or source rpms. If you compiled your KDE, then Kopete must go in the same prefix as KDE did. If, however, you compiled the source packages, then make sure that your Kopete is installed in the same location as your KDE, if it is not, you can force it to do so by specifying a --prefix command to ./configure. e.g. ./configure --prefix=/opt/kde3 (where /opt/kde3 is your prefix). To determine where your KDE prefix is, type "which konqueror" in a konsole. It should display something like "/opt/kde3/bin/konqueror", then /opt/kde3 would be your prefix, or if it says "/usr/bin/konqueror", then your prefix would be /usr. Also make sure you performed a 'make install', and check that there is no stale Kopete installation from previous versions in different locations. You might also need to run 'kbuildsycoca' manually after installing Kopete. kbuildsycoca updates the plugin database. It runs when new software using plugins is installed, but it is possible that 'make install; kopete' will run Kopete before the update has completed.