Re: OneNote 2007

-Exit OneNote.
-Find the corrupt section file via Windows Explorer (probably in Documents-->OneNote Notebooks).
-Make a backup copy of this file just to be safe.
-Shift+right-click the original file and select "Copy as path".
-Click Start and select Run.
-Type onenote.exe /forcerepair, then a space, then Paste the path to the corrupt file.

Alternative variants are:
****SPAMWICH LINKS REMOVED****