Sync attempts result in errors like
The reason for this is that you need some more directives for Apache. Go to the root folder of the ownCloud application on the web server and open .htaccess; there add these lines:
<Limit GET POST OPTIONS PROPFIND PUT DELETE MKCOL MOVE>
Allow from all
<LimitExcept GET POST OPTIONS PROPFIND PUT DELETE MKCOL MOVE>
Deny from all
This should resolve the sync errors from that moment on...
I noticed that after an update (or was it after I changed a setting in the admin's admin page?) the .htaccess was overwritten and the above changes were lost...? I'll add a note to the ownCloud community ...