I always update wordpress manually by doing the following steps:
- Backup Files and SQL
- Download locally the new wordpress files
- Copy ALL files from the ZIP to the folder via FTP and overwrite ALL
- Open /wp-admin/upgrade.php
That worked the last 10 upgrades like a charm.
What happens EXACTLY when doing the automatic upgrade?
What happens with files that are not needed anymore?
What happens to my custom themes?