Reply To: Table of contents has strange formating when include book contents is checked.

From the look of what you posted on the Adobe forum, I suspect you have overrides on the Heading paragraphs in your various documents that come out “weird” in the TOC. It's a misfeature of the TOC function that if any overrides are present in text that is in the styles list for the TOC, it will be reproduced in the TOC. (E.g., If you have a 48 pt. chapter title and you tighten the leading to 48 pt., you get 48 points of leading in the 12 pt. TOC entry for that chapter title. It's infuriating, but according to the Adobe engineer I corresponded with on the subject, it's “as designed.”)

Synchronizing styles across the book document doesn't affect any local overrides, so first remove any overrides in your headings (click inside the paragraph and Alt/Option-click the paragraph style name) in each document, then synchronize the documents with your style source once again, just to be sure, then try the TOC again.

I'll post this on the Adobe forum, too, for you.