Drive stops down sync on share and local move operation.

Share a folder in web, which leads to remote scan in drive, mean time move to other location. Further changes in web are not downsynched.

Steps to reproduce:
Drive Step 1: Configure Drive and Sync all files.
Drive Step 2: Drag and Drop Folder "HelpFiles" with 11 pdf files under User one.
Drive Step 3: Wait for all files synced to server.
Drive Step 4: Create folder 'Userone\CPO' and wait until it sync to the server.
Web Step 5: Share folder 'HelpFiles' with 'ManageEverything' to User2.
Drive Step 6: Wait for 30 Seconds (Permission change will send an security updated event, which will trigger remotescan on Userone\HelpFiles)
Drive Step 7: Move folder 'Userone\HelpFiles' into 'Userone\CPO' which should be 'Userone\CPO\HelpFiles'
Drive Step 8: Wait for changes to sync in server 'Userone\CPO\HelpFiles'.
Web Step 9: Create a folder in 'Userone\CPO\HelpFiles\NextRelease'

Note: Steps 5 to 7 is crucial, it is timing based.

Current Behvaiour: 'NextRelease' folder is never synced to Drive
Expected Behvaiour: 'NextRelease' folder should be synced to Drive

Please find the attached latest logs with 2.1.914 logs in trace mode.
Note: Steps 5 -7 is crucial, it is timing based. Once exception occurs none of the contents will be down synced.

DB Details: Configuration Table.

Exception:

2016-11-16 17:05:11,742 5928 4616 DEBUG    nxdrive.engine.watcher.remote_watcher parent_path: '/org.nuxeo.drive.service.impl.DefaultTopLevelFolderItemFactory#/defaultSyncRootFolderItemFactory#default#39e67008-3928-4826-ba19-bb91767c7c56'	'defaultSyncRootFolderItemFactory#default#39e67008-3928-4826-ba19-bb91767c7c56'	'/org.nuxeo.drive.service.impl.DefaultTopLevelFolderItemFactory#'
2016-11-16 17:05:11,742 5928 4616 DEBUG    nxdrive.engine.watcher.remote_watcher scan_pair: parent_pair: StateRow[2](Local: u'/User one', Remote: defaultSyncRootFolderItemFactory#default#39e67008-3928-4826-ba19-bb91767c7c56, Local state: synchronized, Remote state: synchronized, State: synchronized)
2016-11-16 17:05:11,743 5928 4616 ERROR    nxdrive.engine.watcher.remote_watcher columns remote_ref, remote_parent_ref are not unique
Traceback (most recent call last):
  File "nuxeo-drive-client\nxdrive\engine\watcher\remote_watcher.py", line 460, in _handle_changes
  File "nuxeo-drive-client\nxdrive\engine\watcher\remote_watcher.py", line 406, in _partial_full_scan
  File "nuxeo-drive-client\nxdrive\engine\watcher\remote_watcher.py", line 158, in _scan_pair
  File "nuxeo-drive-client\nxdrive\engine\dao\sqlite.py", line 1058, in insert_remote_state
  File "nuxeo-drive-client\nxdrive\engine\dao\sqlite.py", line 55, in execute
IntegrityError: columns remote_ref, remote_parent_ref are not unique

The only solution so far is to:

1. stop the client
2. remove the .nuxeo-drive folder or at least delete the client DB.
3. start the client