After a long time not doing a sync with webplanner, I tried it again, fortunately after making a backup and a copy of my database directory.
Well in the webplanner there is some old stuff from my first attempts, with a second device too .
Now I want to sync the actual status to webplanner, and what I see after syncing, the old stuff is back on my device.
It is possible to select sync with a "complete download", what I am missing is to select sync with a "complete upload" overwriting the library of webplanner.
Regards
Hartmut