In my case I had to uninstall kde-config-gtk-style and install gtk2-engines-qtcurve to make it work.
I have all three installed:
i gtk-qt-engine - theme engine using Qt 4 for GTK+ 2.x
i gtk2-engines-qtcurve - This is a set of widget styles for Gtk2 based apps
i A kde-config-gtk-style - KDE configuration module for GTK+ 2.x style selection
I suppose that un-installing kde-config-gtk-style just means you can't fiddle with the settings, and therefor the script will not be generated, and you'll just run on the default settings, which works fine. Or is that how it works? Do you now have nice qt styles for your gtk applications?