Word 2010 Multilevel list - Numbers disappear

This is a annoying bug in Office 2010. Use the Organizer to copy the Heading styles from a previous version of the document. To find the Organizer, include it into the ribbon (File -> Options -> Customize Ribbon ->(All commands) -> Organizer. Clcik on the Organizer in the ribbon. In the right pad, Close the Normal.dot and Open File to browse for a former version of your document, selecting "all Files" in the lower right corner.  Copy the headings that do not number correctly, it is often sufficient just to select the higher level heading.

Since copying to a new document worked, corruption may have been the underlying problem.

However, it is difficult to tell without knowing more about the document. For example, did you set up numbering according to the instructions in Shauna Kelly's article at http://shaunakelly.com/word/numbering/numbering20072010.html? Did you avoid using Quick Style sets?

If possible, you can upload an example of the problem document (remove any sensitive information first) to OneDrive or Dropbox and post a link here.

I just read through all the suggestions and what I ended up doing because nothing else worked, was to copy and paste the document into a new word document. When I copied the document, I made sure I did not copy the last paragraph mark in the document.  This seemed to work and make me wonder if somehow the document is getting corrupted.

Sure wish Microsoft would fix this problem and save all of us the time and headaches!!

It hasn't been confirmed by Microsoft (as far as I know), but experience tells me that Quick Style sets are unreliable with numbered and bulleted styles. Multilevel numbering is even more complex, so I'm not surprised that it is breaking when you use style sets.

For assistance with setting up a multilevel list, see http://shaunakelly.com/word/numbering/numbering20072010.html. Save the file as a template; that way, you can easily create new documents with the same numbering scheme.

To transfer the multilevel list to an existing document, create a new document based on your template and then bring in the existing content via the Insert File dialog box.

You can display the Insert File dialog by clicking the arrow on the Object button on the Insert tab and then clicking Text from File (note that the command is misleading, because it doesn't insert only text).

If you are applying style sets to the document, note that these do not work reliably with numbered and bulleted styles. Avoid them and modify styles directly in the document instead

I'm having a very similar problem, and your statement here seems to be key. I'd like to confirm that this is indeed a bug. I inherited hundreds of documents that used a template where different styles are unrelated (single-level) lists. I modified the template so that these styles are multi-level. They now restart numbering as desired. When I apply the new template to the existing docs, it destroys the multilevel lists. Am I to understand that there's no way to avoid this (short of rebuilding the multilevel lists in every document)?

Answers to likely questions: Windows 7, Word 2010, yes I cleared Automatically Update Styles, yes the styles have the exact same names.