I'm running KDE 4.14.21 on Slackware64 14.2. When I go to System Settings > Application Appearance > Icons, select "Adwaita" theme > Apply, it does not show "Adwaita" icons on my desktop. Rather, it shows "Oxygen" theme icons instead. Selecting any of the other themes, (HighContrast, Momochrone, Tango, ...) does show the corresponding theme, just not Adwaita -- which is the one I want. I'm running my desktop layout in "Folder" mode.

Any ideas on how to fix this? Do I need to download something? Rename a config folder? Settings?

Good news, more or less. Perusing the https://bugs.kde.org site gave me the hint to try setting the icon theme multiple times and try logging out and back in. After a couple of iterations of this it finally worked. Some pain and suffering (and patience) required, but I at least have a way to get it done.