After upgrading from Fedora Core 1 to Fedore Core 2, I am unable to run any program which uses gtk, receiving the following error message: <app>: error while loading shared libraries: /usr/lib/libgtk-x11-2.0.so.0: undefined symbol: g_type_class_add_private In looking online, I found a few forum postings which mentioned the error. Sometimes it was due to having an old gtk version (or a related library) installed at the same time as a newer one. In my case, I did not find an old library and all of my packages seemed to be up to date. I used rpm to remove gtk+, gtk+-devel, gtk2, gtk2-devel, libgnome, pango, pango-devel, glib, glib-devel, glib2, glib2-devel, atk, atk-devel, and nautilus, and then used yum to install them, which gave me the output: Installed: pango 1.4.0-2.i386 glib-devel 1:1.2.10-12.1.1.i386 nautilus 2.6.0-4.i386 pango-devel 1.4.0-2.i386 gtk2 2.4.0-1.i386 glib2 2.4.0-1.i386 gtk+ 1:1.2.10-29.1.1.i386 glib2-devel 2.4.0-1.i386 libgnome 2.6.0-3.i386 atk-devel 1.6.0-1.i386 gtk+-devel 1:1.2.10-29.1.1.i386 glib 1:1.2.10-12.1.1.i386 gtk2-devel 2.4.0-1.i386 atk 1.6.0-1.i386 All of these seem to be up to date, or at least more up to date than the files which were causing problems in the forum post I found (http://www.linuxquestions.org/questions/showthread.php?s=&threadid=177883). I have asked about this a few times in #fedora on freenode, but no one has been able to come up with a solution. Someone suggested that I might have conflicting repositories, but after looking at them decided that they should not conflict. I am currently using: Server: Fedora Linux 2 - i386 - core Server: Fedora Core 2 -- Fedora US mirror Server: Fedora Linux (stable) for Fedora Core 2 -- Fedora US mirror Server: Fedora Core 2 updates -- Fedora US mirror Server: Fedora Linux 2 - i386 - freshrpms Server: Fedora Linux 2 - i386 - updates This problem began to occur immediately after upgrading from Fedora Core 1 to Fedora Core 2, using the four i386 isos. So, the idea of conflicting old versions causing problems does make sense - but I can't find anything that should cause a problem. If anyone has any suggestions, or needs additional information, please contact me. -Ian