Comment 2 for bug 157207

As far as I can remember, the Pidgin synchronisation plugin is extremely simple, and the entries will have to match exactly (between Pidgin and the Contacts). If they do not, then the plugin will re-add them. If you have it running periodically... it may get worse. I think this was a bit changed on 2.22, so indeed it would be good to test there.

Right now I would disable this plugin.