Now that kde-4.2 upstream ships with desktop effects enabled by default, to avoid regressions and surprises, we need to modify kde-settings to keep desktop effects disabled by default.
OK, the deed is done, pkgs ready for inclusion in updates: F-9: kde-settings-4.0-31.20090126svn.fc9 F-10: kde-settings-4.1-5.20090126svn.fc10
Fixed in the latest 4.2 testing update, 4.1 not affected, closing.