http://forums.fedoraforum.org – There seems to be an incompatibility between Eclipse-3.5.1 and GTK that ships with Fedora 12 Often buttons don't react on mouse click. When the botton is highlighted,hitting enter however works. Code: $ yum list installed | grep gtk2 gtk2.i686 2.18.3-21.fc12 @updates gtk2-engines.i686 2.18.4-4.fc12 @rawhide gtk2-immodule-xim.i686 2.18.3-21.fc12 @updates libcanberra-gtk2.i686 0.22-1.fc12 @rawhide pygtk2.i686 2.16.0-1.fc12 @rawhide pygtk2-libglade.i686 2.16.0-1.fc12 @rawhide Various other posts in eclipse bugzilla point out that there might be an incompatibility with gtk-2.17.x and above This issue seems to be fixed in eclipse-3.6M3 http://download.eclipse.org/eclipse/downloads/ (HowTos)