CFBookMarkMBS and NSEventMBS

I’m using a combination of cfBookmarkMBS and nsEventMBS to achieve 2 things:

  1. To reload folderItems on restarting the app - so that it avoids sandbox problems
  2. To identify when external folderItems are removed or re-mounted - so that their availability is correctly indicated on the app.

The first one works fine - when the app is opened it correctly makes folders available or not, if they are online or not.
The second one is problematic - I do get an FSEvent when something is removed, and another set of events when it is re-mounted - but I can’t get the bookmark to re-open (at least I think that is the problem) - the folderitem.exists property stays as false.

If I close and re-open the app it shows the items correctly again. I’ve tried replicating all the app does when closing and re-opening (releasing the bookmark and re-creating the bookmark from its cfURLMBS) - but to no avail.

Does anyone have any experience in getting this to work?