I decided to upgrade Drupal today mostly because of security fixes. First to 5.10, then to 6 as I was already at it. It turns out that Drupal 6 needs at least MySQL 4.1 but our RZ still runs 4.0 which is bugging me for more than two years. So I needed to revert back to 5.10. Suddenly my content was gone. Instead I would see "n/a" ("n/v" in the translated version). Google didn't give results that delt with my problem. After working on this for more than 2 hours I solved it: "Problem Exists Between Chair And Keyboard."

Doing a backup I do a full SQL dump. When restoring I can't use locking as our RZ wouldn't give us locking rights (which makes me patch Drupal for more than two years). I do a "grep -v 'LOCK TABLES' though I should've done a "egrep -v '^LOCK TABLES" as I deleted the hugh table of content: table node_revisions was completely missing.