Master document numbering

[SomersetGraham]

Hi
I am in the process of setting up a Master document and several sub model document elements.
I want to have continuous numbering between them, I have had this working once but dont seem to be able to reproduce it.
I have created a list override and saved this to normal.rtf.
I have created a master documnet and added a couple of sections -

1 Heading 1
1.1 Heading 2

Now I have created a model document and added a section at level 2 (ie 1.1)

When I generate the document the numbering for rhe model document starts at 1.1

So what i get is
1 Heading
1.1 Heading 1 (from master)
1.1 Heading (from model document - should be 1.2)

Any idea what I am doing wrong?

Graham