Two solutions you can try.
1. If you have installed xfce, this desktop environment uses xfce-mcs-manager for a sleeker rendition of GTK2 applications so just issue the command: /usr/bin/xfce-mcs-manager to instantly smoothen things up. Of course you may choose to have this run automatically when you start up (a) KDE, (b) X or (c) your system. For (a) create a file in ~/.kde/Autostart and place the above command in it. Make the file executable chmod +x filename. (You can later place any command you wish to execute when KDE starts up as a line in the file). I am not too sure how to go about (b) but for a system wide auto-start, I guess you can place the command in rc.local.
2. You can install the gtk-qt-engine package, last time I checked I found a version gtk-qt-engine-0.7-i486-1asz.tgz somewhere. I can't say whether it will work on Slack 12 though. Anyway, after it has been installed, an entry will be made in the KDE Control Center menu, (under themes I think but not too sure) will enable you to set the appearance of your GTK2-based apps.
Last edited by dizzi; 07-19-2007 at 08:41 AM.