[XeTeX] XeLaTeX-Beamer problem

[Alan Jones]

Hi:

I am trying to compile Beamer with XeLaTeX. I get this error.

! Undefined control sequence.
\pgfsys at beginpicture ...{\pgfutil at font@normalfont
                                                  \pgfutil at selectfont .\hss ...
l.18 \frame{\titlepage}

How can I resolve this.

Thanks,

Regards.
Alan