Users are complaining about the Folders List - it's behavior indeed sometimes is quite annoying.

Steps to reproduce:

Add Folder "New Folder" in "Cabinet" - no problem
Add Folder "New Folder2" "New Folder": "New Folder" stays closed, still not really a problem
Add Folder "New Folder3" in "New Folder2": all "New Folders" are closed - and have to be reopened step by step to get to "New Folder3"
... and so on

Open "New Folder3". Drag mail from "Mailbox" to "New Folder3" - again all "New Folders" are closed.

Is it a bug?