-b option on rsync with HFS support

[Chuck Benson]

OS X 10.4.6 (BSD)

I was using the 'standard' versions (i.e. non-HFS supporting) of  
rsync with the backup -b option so that I could do nightly  
incrementals.  This seemed to be running fine. Changes to existing  
backed up files got copied to the appropriate path(s) on the target.

BUDIR=myDirectoryName
time /usr/local/bin/rsync -a -b --suffix=# --backup-dir=$BUDIR / 
Users /Volumes/nephron

However, when I started using a version (2.6.0 protocol version 27)  
supporting HFS and choosing the extended attributes option, the sync  
works, but the copy to the backup directories doesn't work unless the  
path is already there.

time /usr/local/bin/rsync -eahfs -a -b --suffix=# --backup-dir= 
$BUDIR /Users /Volumes/nephron

That is, it appears that the non-HFS version creates the backup  
directory path if needed, but the HFS-supporting version does not  
automatically create the path.  However, if the path is already  
there, the non-HFS version does make a good copy.

Anyone else seen this?  Any suggested workarounds?

Thanks