--suffix problem - possibly bug?

[Jim Salter]

I'm having an issue with the --suffix and -b flags -

I've tried the following commands:

rsync -avbr --backup-dir=/rsyncbackup rsynctest user at server.com::module

rsync -avbr --backup-dir=/rsyncbackup --suffix="" rsynctest 
user at server.com::module

and either way, I wind up with a tilde as a suffix on all the files 
moved into the backup directory at time of synchronization.  According 
to the man page, if --backup-dir is specified, the default suffix should 
be a null character - but that's not what I'm discovering; I'm 
discovering that I CANNOT find a way to specify no suffix.  I can 
successfully specify a DIFFERENT suffix - such as --suffix=.rsync - but 
I can't manage to specify no suffix at all.

For reference, I'm issuing the rsync commands from a Windows 2000 laptop 
using cwrsync (based on rsync 2.6.0), and the server on the other end is 
a FreeBSD 5.1 machine running rsync 2.6.0 from the ports tree.

Thanks ...

Jim Salter
JRS Systems