Hey,
Can't seem to start jackd in realtime as user on ubuntu studio. It
does start as root, but that's hardly a consolation (unless I run all
audio software as root, which would be kinda daft IMO)
...
Have you tried modifying /etc/udev/rules.d/something (debian/ubuntu) or
/etc/security/console.perms.d/60-raw1394.perms (fedora)? Make sure you
assign your security group (audio?) to the /dev/raw1394 device.
-Scott