+++ This bug was initially created as a clone of Bug #670517 +++
Trying to drop a contact on another address book fails with the below error message since SM 2.2:
Error: gDirectoryTreeView is not defined
Source File: chrome://messenger/content/addressbook/abDragDrop.js
This is fallout from bug 422845 (gDirectoryTreeView is TB-only to date).
Bug 654864 will fix this, but only land on trunk, so the SM versions in between would all continue to be broken.
*** Bug 671551 has been marked as a duplicate of this bug. ***
Bug 654864 just landed on comm-beta, i.e. it will be in SM 2.3 (but probably not 2.3b1).