Using FF 3.0.6

How can I get the folders in my bookmarks list to list
alphabetically? I can go to Organize Bookmarks, see the Windows
Explorer style page open and make the list sort A->Z, but it doesn't
remain that way when I go back to FF.

In my main list, I have folders and non-folder entries. I want to see
them as the folders sorted A->Z first, then the non-folder entries
sorted A->Z.

Is that possible?