Hi Boris,

>The trigger looks OK, but did you have recursive triggers enabled?

I've never heard of them. Is that a setting somewhere that can be switched on for the database?

>How many levels of parenting you may have?

It only goes one level deep.

>What if you delete a child that has siblings?

If a child is deleted, nothing else happens to the siblings. If a parent is deleted, then all children must be deleted.