Please see this screenshot:

http://screencast.com/t/GFJMAzAis9v

As you can see, I will bold some text in any section which starts off as #1 (like section #2, #3 etc.)

I will edit the rest of the document and the boldness has disappeared but only for section #1. This happens for multiple sections in the document using the same styling.

What could be causing this please? Any pointers would be much appreciated.

Thank you!