Customer experienced an issue with depth field of ezcontentobject_tree table which isn't updated after moving content. It applies only to content located under 'eZ Platform' folder (content object id = 1) which is provided with the clean installation.

Steps to reproduce:
1. Create a clean installation of eZ Platform 2.1.
2. Create two content objects (e.g. articles) under 'eZ Platform' folder.
3. Check in the database the value of ezcontentobject_tree.depth field: both articles should have the same value.
4. Move one of the articles under another. E.g. 'eZ Platform' -> 'Article1' -> 'Article2'.
5. Note that ezcontentobject_tree.depth of 'Article2' doesn't change.