Hi, Thomas:
While there's a lot to FrameMaker, it is logical, and often FM provides tools to analyze the logic of behaviors that seem incorrect.
For example, you can quickly identify all the content in the text flow that contains the insertion point, by choosing Edit > Select All, and scrolling through the document to see what is highlighted and what isn't. To display as many document pages as possible in one view, use View > Options > Page Scrolling > Variable, maximize the document window and zoom out to 25%. Anything that's not highlighted is not in the selected flow - it may be in another body page flow, or it may be on a master page.
In a sense, the TOC' behavior correctly analyzed the document's multiple-flow construction.
HTH
Regards,
Peter Gold
KnowHow ProServices