Well, I've seen that post, and I changed the fpc.cfg, too, but nothing happened... :-(
I copied (you must be logged in as ROOT) the following files: opt/gnome/lib/gtk and /gtk2 the whole directories, any library that has a filename which starts with "libgtk" AND "libgdk" in opt/gnome/lib. Just copy them to usr/lib/ . (And don't forget to create the directories gtk and gtk2!)
I did it with Konquerer logged in as ROOT. Just drag and drop the files... ;-)))