Description of problem:
After yum update firefox does nolonger start
Version-Release number of selected component (if applicable):
$ rpm -qf `which firefox`
Steps to Reproduce:
1. type: firefox
2. nothing happens
firefox does not start
When I ran: strace firefox I got a popup abrt message of a crash in xulrunner, which crashed itself...
Further research of the system learned that /usr/lib/libgtk-x11-2.0.so.0.2400.4 was corrupted. After yum reinstall gtk2 everything works again.