--delete ignored?

[va_public <yahoogroups at vikas.mailshell.com>]

rsync 2.5.6

If I turn on the --backup (and --backup-dir and --suffix) options and 
rsync a tree like

rsync --backup ... -av --delete dir1/ user at machine:dir1

I dont see the 'deleting ...' message in the output, but if I delete 
a file in the source tree, it DOES get deleted from the target tree.

If I remove the '--backup' option, I do get the 'deleting ...' 
message.

Why is this?

If the file is getting deleted, shouldnt the --verbose option print a 
message to this effect?

Thanks