how to get around rsync error (OS X Tiger)

[Lee Cullens]

I create a full direct clone with asr and am working at differentially 
updating that clone with rsync. The main problem I have is that unless 
(in rsync) I exclude at least /System/Library/CoreServices/* I get the 
rsync error:

rsync: rename 
"/Volumes/LaCie_Disk_B/System/Library/CoreServices/.BootX.ItPCZ0" -> 
"System/Library/CoreServices/BootX": Operation not permitted (1)
rsync error: some files could not be transferred (code 23) at 
/SourceCache/rsync/rsync-20/rsync/main.c(717)

Occurs on the second (not the first) and following differential clones 
with rsync.

No material that I can find suggests excluding 
/System/Library/CoreServices/* no doubt with good reason, but I do 
already have it on the clone from the full asr clone.  My concern is if 
anything might change in /System/Library/CoreServices/* in-between full 
clones that I should catch in the differential update to maintain the 
consistency of the clone (consistency of system information - not 
directory vs actual data).  

I use asr for the full clone because with the device level block 
transfers is is so much faster.

Is there onother work-around?

Thank you,
Lee C

Dual 2.5 PM G5 OS X 10.4.2
rsync on Tiger is version 2.6.3  protocol version 28