I don’t know if it is a bug or a feature, but it also happens in 2007. You can move items directly to the “Personal Folders” folder, but <b>I didn’t find a way </b>to view those items that are moved directly to that folder and not to a sub-folder.
-From the Find bar open the “Advanced find” tool.
-Click on the “browse” button
-Select “Personal Folders” (make sure no other folder is selected) and uncheck the “Search subfolders” checkbox.
-Don’t add any other search condition
-Click on the “Find Now” button.
If you find those mails, move them to some sub-folder, and tell the user not to move mails to “Personal Folders” again…