MathML <mover> element for accents?

[Duncan Hothersall <dh@capdm.com>]

Hello ConTeXters.

I am using the wonderful ability of ConTeXt to directly typeset MathML 
equations, and have come across a problem with trying to put a line 
above a character using the <mover> element. Here's what I try:

\setuppagenumbering[state=stop]
\starttext
\startXMLdata
<math display="block">
  <mover accent="true">
   <mi>x</mi>
   <mo>¯</mo>
  </mover>
</math>
\stopXMLdata
\stoptext

The output I get is as if the accent="true" attribute wasn't set - i.e. 
the line is a long way above the x, not like an accent.

Is there another way to place math accents in presentational MathML?

My versions:
         TeXVersion 0.1 / Taco Hoekwater 2004
                texexec : TeXExec 4.4 - ConTeXt / PRAGMA ADE 1997-2004
                texutil : TeXUtil 8.2 - ConTeXt / PRAGMA ADE 1992-2004
                    tex : pdfeTeXk, 3.141592-1.11a-2.1 (Web2C 7.5.2)
                context : ver: 2004.8.15
                cont-en : ver: 2004.8.15  fmt: 2004.8.22  mes: english

(PS (Patrick) - I tried to get a minimal file working on 
live.contextgarden but couldn't get any maths formatting to come out. 
Perhaps MathML support is not enabled there?)

Thanks,

Duncan