Help needed on CentOS 4.5 & FireWire/SBP2

[centos_system]

I am running 64-bit CentOS 2.6.9-55.EL on AMD64. I can load the FireWire modules (SBP2, OHCI1394 & IEEE1394) and can see those as well as the partitions created of the FireWire drive using fdisk -l.
If I create an EXT3 on a partition, it's great. But when I try to perfom the following:
dd if=/dev/zero of=/dev/raw/raw1 bs=8196 count=12000 or any dd on any partition on that drive, I am getting:
ieee1394: sbp2: aborting sbp2 command
scsi4: destination target 0, lun 0
command: Read (10) and then bunches of numbers
ieee1394: sbp2: hpsb_node_write_failed
ieee1394: sbp2: Bus reset in progress -- rejecting command

But the dd finishes and I can see the partitions using fdisk -l

I have the following in the /etc/modprobe.conf file:
options sbp2 serialize_io=1 exclusive_login=0

Can somebody please tell me what's going on & how I can avoid these errors?
Thanks for your help.