From Jan Roelof:
As a heavy user of OneNote, I am generally happy with the 2010 version. One of the drawbacks is that most add-ins written for the 2007 version, no longer work for notebooks in the 2010 format, or are unreliable. I am beginning to get familiar with programming for OneNote 2010 and trying my hand at some utilities myself.
The OneNote utility I am sharing here is “OneNote 2010 Sort Utility”. I found that the existing one by Daniel Escapa does not work for my 2010-formatted notebooks.
This utility sorts sections within notebooks and section groups and and (sub)pages within sections. The sorting can be done by name or lastModifiedTime, ascending or descending, and can be done recursively (for sections in section groups in the currently selected notebook or section group, etc) or not. The sorting routines respect subpage structure. For some reason, the section groups themselves apparently cannot be sorted.
The zip-file contains a setup file. Just install and run and you get a treeview of your notebooks. Browse to the notebook, section group, section or page whose sections or (sub)pages you want to sort and press the button.
Requirements: .NET Framework 4, OneNote 2010.