metapost output again

["cali" <calculus softhome net>]

OK, I've been trying to figure out what is wrong, so I made a very simple 
diagram file, with only a line and a text item. I used dia 0.92.2 to output 
to metapost, and dia 0.94, the version can be converted to mps with mpost, 
but the version using 0.94, can't. Examination of the mp files show their 
differences:

################### VERSION 0.92 ######################
% Metapost TeX macro
% Title: C:\Documents and Settings\cali\Desktop\diagrams\test.dia
% Creator: Dia v0.92
% CreationDate: Fri Oct 29 19:21:44 2004
% For: cali


beginfig(1);
 % picture(0.977500,-0.245000)(2.450000,0.772500)
 x = 1.000000cm; y = -1.000000cm;

% set_line_color 0.000000, 0.000000, 0.000000
% set_line_color 1.000000, 1.000000, 1.000000
% set_line_color 0.000000, 0.000000, 0.000000
 label.rt(btex $A$ etex,(1.000000x,0.000000y));
endfig;
end;

################## VERSION 0.94 ###################
% Metapost TeX macro
% Title: C:\Documents and Settings\cali\Desktop\diagrams\test.dia
% Creator: Dia v0.94
% CreationDate: Fri Oct 29 19:22:21 2004
% For: cali

beginfig(1);
verbatimtex
&latex
\documentclass{minimal}
\begin{document}
etex
 % picture(1.000000,-0.300000)(2.200000,0.700000)
 x = 1.000000cm; y = -1.000000cm;

% set_line_color 0.000000, 0.000000, 0.000000
% set_line_color 1.000000, 1.000000, 1.000000
% set_line_color 0.000000, 0.000000, 0.000000
 label.urt(btex {\usefont{OT1}{phv}{m}{n} $A$} etex scaled 
1.67988,(1.000000x,0.000000y));
endfig;
end;

mpost chokes like this:

This is MetaPost, Version 0.641 (Web2c 7.3.7x)
(test2.mpmakempx: Command failed: tex mpxerr.tex; see mpxerr.log

> > test2.mp
> > test2.mpx
! Unable to make mpx file.
l.20   label.urt(btex
                     {\usefont{OT1}{phv}{m}{n} $A$} etex scaled 
1.67988,(1....

Transcript written on test2.log.

But it writes the earlier version perfectly. Maybe I am being dumb here, I 
don't know much about metapost, I just want to blindly use mpost to convert 
the image as expected so I can include it in my latex document. I have found 
that I can still scale text using the etex scaled, but its the usefont bit 
that kills mpost.

Is the person who writes the mpost code on this list? Can somebody tell me 
how I am supposed to convert this 0.94 mp output to mps that can directly be 
included in a latex file for processing with pdflatex.

cali