Have you tuned your irq setup?
Read my little page on the subject
http://tapas.affenbande.org/wordpress/?page_id=40
Thanks Florian, very helpful. Apparently, my ohci1394 device is sharing
interrupts with my internal sound card, my internal modem's sound
device, my Ethernet card, my USB stick, and an unidentified device. I
just asked on the Freebob list how to make ohci1394 use a dedicated
interrupt (or share it with an unused device like ide2 in my case),
maybe you can help as well?
Carlo