Secunia reported a pair of frame injection vulnerabilities that could result in popup blocking. http://secunia.com/secunia_research/2004-13/advisory/ https://bugzilla.mozilla.org/show_bug.cgi?id=273699 This issue should also affect FC2
The secunia demo no longer works. I've created a demo located here http://people.redhat.com/bressers/spoof_test/
Fixed in latest mozilla release version.