[Faun]

the probable solution;
http://ubuntuforums.org/showpost.php...48&postcount=4
Solution:

I was poking around the ~/.gtkrc-2.0 for the first time actually and it looked like this:

---
# This file was written by KDE
# You can edit it in the KDE control center, under "GTK Styles and Fonts"

include "/usr/share/themes/Clearlooks-DeepSky/gtk-2.0/gtkrc"

style "user-font" {
font_name="Sans Serif 10"
}

widget_class "*"
style "user-font"
gtk-theme-name="Clearlooks-DeepSky"
gtk-font-name="Sans Serif 10"
---

When I remove or comment out the include part I can finally get all my GTK themes working perfectly. Except for some Clearlooks_Cairo themes which seem a bit broken without that include.

original thread

http://ubuntuforums.org/showthread.php?t=247555