I had a report from a debian user that his rsync job stopped leaving deleted files behind (with the suffix appended) when he upgraded from 2.6.3. (See URL for his full message). I've confirmed this. Additionally, I discovered that when also using --delete-after, the backup suffix needs to be --exclude-ed, otherwise the backup is deleted after being created, during the same run...
It helps to look at the NEWS file from CVS so that you won't duplicate bugs that have already been fixed (this is mentioned in the checklist on the bug-reporting page, complete with a link to the unpacked NEWS file). As for excluding the backup suffix when using --delete-after, that has always been required -- I've considered adding an automatic exclude for it, but have left it compatible with older versions for the time being.
Created attachment 1202 [details] Fix the combination of --backup with --delete-after