Using Word 2000 on Windows 2000.

My file is about 250 pages and contains a lot of tables and complex
Word diagrams, so it's probably close to being corrupt anyway. :-)

Here's the problem: I insert a Table of Contents, format it, and
then do a number of different things--only to find that the ToC
loses its formatting. Most entries lose the formatting--not all.

This isn't predictable--the formatting might go away (or not) if you
open/close/open the document. Updating the ToC doesn't make the
formatting go away--nothing does consistently. It just goes away on
a whim.

I used to just re-enter the definitions of the TOC Styles whenever
this happened, but that was easy to do when we only had three or so
levels of entries in the ToC. Now that we have 7 entries, this is
more difficult and time consuming.

I wonder if anyone here has seen anything like this before...if so,
do you have any tips?