I activated the general log in MySQL and proofed what SQL is send to the server in the problematic updates.
In case of wikimedia no clear update command is send, but in phpbb i could see that the update is blank instead of the content.
1339 Query UPDATE phpbb_topics SET topic_title = '', topic_type = 0 WHERE topic_id = 1066 The topic_title should contain a text. Something goes wrong in PHP5. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org