The 'Region' field (The region of the page this block should appear in), in the form, fails to show available regions - just says <none> and the following error appears when the content is saved:
The block Name was assigned to the invalid region -1 and has been disabled.
Consequently you have to return to the Blocks Settings page to replace the node in its proper region whenever the node is edited.
Comments
Comment #1
Chris Lozinski commentedJust seen this
http://drupal.org/node/360033
Not a bug then.
Comment #2
dropcube commented