conflicting styles - how to force a plain style

[Tim Duke]

Hi,

I've got a doc that is mostly an outline like this - several levels  
of headings and at the deepest (="youngest", or "childless", using  
the parent/child metaphor) there is plain text.  The trick is: this  
plain text can exist at most levels: ie:

Heading 1
	SubHead 1
		SubSubHead 1
			plain text item 1
			plain text item 2
	SubHead 2
		plain text item 1
		plain text item 2
Heading 2
	plain text item 1

How do I most easily use styles to format this?  Currently I make all  
level 1 to be Headings style, level 2 to be subheadings, level three  
to be subsubheadings, and level 4 to be plain text.  Then I manually  
force the youngest rows in Levels 1,2,3 to plain text.  This is  
fairly painful.  Then, using the named styles features of  
OmniOutlinerPro, I thought I could define a style "plain", but this  
isn't working for me at the moment.  The reason why is this:

At the moment I've got
	Headings in big and bold and underlined
	Subheadings in italics and bold, not underlined
	SubSubheadings in italics, not underlined or bold
	and plain text in just plain, not bold, or italics, or anything.

Now if I define a style "plain"  - which is listed in the Inspector  
as a one-line "Font Family...", it seems to be over-ruled by the  
italics and bold options of its parents.  In other words, applying  
the style "plain" doesn't really force plain text.  I have to  
manually adjust the rows in question by extinguishing each style  
item.  I assume this happens because OmniOutliner thinks that these  
styles can co-exist peacefully.

Is there a better way to do what I want?
Thanks,

Tim