It appears that the ebuild for libdc1394-2.0.0 is building the library with juju support even when the use flag is -juju. This won't work if the kernel is using the old firewire stack (from David Moore on the libdc1394-devel list). Note that 2.0.1 is also released now. Thanks! Reproducible: Always
related thread at libdc1394-devel: http://sourceforge.net/mailarchive/forum.php?thread_name=49822.12463.qm%40web32103.mail.mud.yahoo.com&forum_name=libdc1394-devel
Thanks for reporting. The problem was that --without-juju-dir was translated to --with-juju-dir=no, which enabled the juju stack. Fixed in libdc1394-2.0.0-r1.