Solution for alphabetizing folders.
There should be a Hidden/System file called "OneNote Table Of
Contents.onetoc" in *each* folder. This file stores among other
things, the placement of folders and sections in the current folder.
See if that file exists or has its modification date changed after each
time you arrange your folders in OneNote. Remember that this is a
hidden file, so you must have Explorer configured to see these files
(Tools | Folder Options | View | "Show Hidden Files and Folders").
=== Solution for alphabetizing sections/folders===
If you don't care for sections' color you can blow away the current
order (and color) like this, warning - it's a hack):
1. In Windows Explorer set to show hidden files
2. Close OneNote
3. Navigate to the folder you want sections to be in alphabetical order
4. Delete *.toc file in this folder
5. Boot OneNote
There is no way in OneNote UI to do this.
Can someone verify this works.