[XeTeX] Dollar signs in Adobe OTF fonts

[Easter Sunshine]

I seem to be missing something quite simple. The following short .tex file produes unexpected results with xelatex:

%&program=xelatex
%&encoding=UTF-8 Unicode

\documentclass{article}

\usepackage{fontspec}
\newcommand{\MAINFONT}{Minion Pro}
\setromanfont{\MAINFONT}

\begin{document}
\$30.
\end{document}

The relevant part of the log file, I think, is:

LaTeX Font Info:    No file OT1Minion Pro(0).fd. on input line 11.
LaTeX Font Info:    Font shape `OT1/Minion Pro(0)/m/n' undefined
(Font)              using `OT1/cmr/m/n' instead
(Font)              for symbol `textdollar' on input line 11.

I have attached them also. I have been googling for both "dollar signs in xe(la)tex" and the error message itself. It seems that this problem is usually with OTF and LaTeX, not XeLaTeX. I don't remember reading anything in the docs about this, I thought OTF fonts were supposed to "just work." I even tried blindly putting in \usepackage[EU1]{fontenc} and some other stuff, but still I get strange words before dollar signs and before enumerate environment's bullets. What can I do?

Easter Sunshine.

 __________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://tug.org/pipermail/xetex/attachments/20071025/566d50c0/attachment.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: test.tex
Type: application/x-tex
Size: 190 bytes
Desc: 2461066665-test.tex
Url : http://tug.org/pipermail/xetex/attachments/20071025/566d50c0/attachment.tex 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: test.log
Type: application/octet-stream
Size: 11621 bytes
Desc: 236009500-test.log
Url : http://tug.org/pipermail/xetex/attachments/20071025/566d50c0/attachment.obj 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: test.pdf
Type: application/pdf
Size: 5196 bytes
Desc: 413810342-test.pdf
Url : http://tug.org/pipermail/xetex/attachments/20071025/566d50c0/attachment.pdf