Inserting new paragraph by placing the cursor at the beginning of a paragraph is reading the Next Pgf Tag setting and changing the existing paragraph's style. For example, consider that you have a Heading 1 and want to insert another Heading 1 above it. You used to be able to simply place the cursor at the beginning of the existing H1 and press Enter. Voila - two H1 paragraphs.
Now when you do this, the existing H1 becomes Body style, because Body is the Next Pgf Style setting for H1. The same is true for any paragraph tag with a different Next Pgf setting.
This is a change since FM8 (we just upgraded to FM12 last year), and I suppose Adobe thinks they made the setting smarter, but we find this behavior not at all useful.
If there is a workaround to this (other than the obvious), we'd sure like to hear it. It's a small thing, but irritating. (And if no solutions, yes we will report this in the Bugs/Features area.)
Thanks!