simple incremental backup woes. solutions?

[The Peach]

Hi all,
 I've finally hit rsync limit. As someone already addressed the problem in this list the problem regards the impossibility for rsync to rename directories.
The situation is as follow:
every night I backup my samba dir with this command:

rsync -ab --suffix=-`date +%F-%H%M` --filter="protect *-[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]-[0-9][0-9][0-9][0-9]" --delete --numeric-ids --stats -h /home/samba/ /mnt/usbdisk

as you can see, I simply rename the files deleted with the date they've been found deleted, hence providing a protect filter for the files with a date at the end (as you might imagine the machine serves windows clients).
Obviously (!) when a directory is deleted on the source dir, all the files in the destination will be renamed, but the dir will not, and rsync tries to delete it ending with a "cannot delete a non-empty dir".

I'm asking here because I need even a dirty solution to this problem.
I've been addressed to rsnapshot, but seems hard to replicate the same backup type I've setup, so I gave it up.

Any suggestion, solutions and such will be very much appreciated.

Thank you in advance,


-- 
Matteo 'Peach' Pescarin