As in the subject. yum definitely dislikes version 7.21.2-1.fc15 of libcurl and refuses to run but no dependencies prevent that update (soname in libcurl does not change while ABI apparently does). Reverting to 7.21.1-6.fc15 fixes the problem. Bugzilla https://bugzilla.redhat.com/show_bug.cgi?id=642796 Michal