Hello,
I don't have an antivirus setup, no.
I did find a solution though. I followed this topic: http://support.feed-the-beast.com/?qa=2059/ftb-launchers-crashes-no-crash-report-mac-osx-10-7-5-java-7u9 to get back to the 1.6 version of Java instead of 1.7. This, plus deleting the feed the...