Further to my previous query about updating from mkii to mkiv, I have solved some of the issues by trial and error but am beginning to identify the ones I can't resolve. My first minimal example is below.

I want the sections and subsections not to prefix the part and chapter numbering, giving me this output:

Part 1
Chapter 1.1
Section 1
Subsection 1.1

The line that used to achieve this result was

\setupsection[section-3][previousnumber=no]

and there was also 

\setuphead[section][partnumber=no,chapternumber=no]

but neither of these seems to work in mkiv


Minimal example: 

\setupsection[section-3][previousnumber=no]
\setuphead[section][partnumber=no,chapternumber=no]

\starttext
\part{Part}
Part
\chapter{Chapter}
Chapter
\section{Section}
Section
\subsection{Subsection}
Subsection
\stoptext

Many thanks for any pointers.

Duncan