Hi,
I had the same problem in Suse 9.3. Here is what I found:
1- Suse has a BAD support of GTK-1. Everything works well with GTK-2 but GTK-1 has NO control center: the module "control-center-2" is for GTK-2 but the module "control-center" for GTK-1 does NOT nork. The application "gnomecc" will call another application "theme-selector-capplet" which is not supplied anymore.
2 - I have tried to install "theme switch application" from the web:
http://themes.freshmeat.net/browse/923/ but it did NOT compile either. I think this is a debian application.
3 - I have rebuilt lazarus using GTK2 as the widgetset! This works!
I do not know in which state of development GTK-2 is but I think that GTK1 is in the past now !! Too bad. In Mandriva, the GTK1 theme is very nice that I never needed to change it, but in Suse, the solution will be to go to GTK2 as soon as possible.