ettercap-gtk segfaults (or something similar) immediatelly after performing host scan. This problem makes ettercap-gtk useless. It is reported and fixed upstream: http://sourceforge.net/tracker/?func=detail&aid=3532440&group_id=17435&atid=117435 so it is necessary to either backport patch or compile ettercap_rc git version.
It looks like the git branch is the way to go, but they changed build systems. Working on it.
ettercap-0.7.5-0.fc18.20120905gitc796e5 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/ettercap-0.7.5-0.fc18.20120905gitc796e5
ettercap-0.7.5-0.fc17.20120905gitc796e5 has been submitted as an update for Fedora 17. https://admin.fedoraproject.org/updates/ettercap-0.7.5-0.fc17.20120905gitc796e5
ettercap-0.7.5-0.fc18.20120906gitc796e5 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/ettercap-0.7.5-0.fc18.20120906gitc796e5
ettercap-0.7.5-0.fc17.20120906gitc796e5 has been submitted as an update for Fedora 17. https://admin.fedoraproject.org/updates/ettercap-0.7.5-0.fc17.20120906gitc796e5
Package ettercap-0.7.5-0.fc17.20120906gitc796e5: * should fix your issue, * was pushed to the Fedora 17 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing ettercap-0.7.5-0.fc17.20120906gitc796e5' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2012-13448/ettercap-0.7.5-0.fc17.20120906gitc796e5 then log in and leave karma (feedback).
ettercap-0.7.5-1.fc18.1.20120906gitc796e5 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/ettercap-0.7.5-1.fc18.1.20120906gitc796e5
ettercap-0.7.5-1.fc17.1.20120906gitc796e5 has been submitted as an update for Fedora 17. https://admin.fedoraproject.org/updates/ettercap-0.7.5-1.fc17.1.20120906gitc796e5
ettercap-0.7.5-1.fc18.1.20120906gitc796e5 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report.
ettercap-0.7.5-1.fc17.1.20120906gitc796e5 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.
ettercap-0.7.5-2.fc17.1.20120906gitc796e5 has been submitted as an update for Fedora 17. https://admin.fedoraproject.org/updates/ettercap-0.7.5-2.fc17.1.20120906gitc796e5