[XeTeX] Textbullet problem

[snvv]

Hello,

Using fontspec and xunicode the \textbullet is small or at least smaller than 
without the fontspec and xunicode.

The problem is clear if you run the files

\documentclass[dvipdfm]{report}
\usepackage{fontspec}
\usepackage{xunicode}
\begin{document}
\textbullet aaa
\end{document}

and

\documentclass[dvipdfm]{report}
%\usepackage{fontspec}
%\usepackage{xunicode}
\begin{document}
\textbullet aaa
\end{document}

Regards
Sotiris

PS. XeTeXk, Version 3.141592-2.2-0.996-patch2 (Web2C 7.5.6)