[XeTeX] Strange tikz behaviour with xetex

[Akira Kakuto]

Dear Vafa Khalighi,

> \documentclass{article}
> \usepackage{atbegshi}
> \usepackage{tikz}
> \AtBeginShipout{%
>  \AtBeginShipoutUpperLeft{%
>  \put(0,0){%
> \tikz[remember picture, overlay]\shade[top color=blue!15, bottom
> color=blue!80] (current page.north east) rectangle  +(-5,-28);
> }}}
> \begin{document}
> This is a test
> \newpage
> This is a test
> \newpage
> This is a test
> \newpage
> This is a test
> \end{document}
> 
> 
> You see that shaded rectangle on every single page of the document.
> However, if you run xelatex, that rectangle does not appear on the
> first and second pages. What is wrong?

Probably because pgfsys-xetex.def and/or pgfsys-dvipdfmx.def,
which are used by XeTeX, are incomplete.
I think there are other tikz examples in which XeTeX cannot
reproduce results by pdfTeX.

-- 
Best regards,
Akira KAKUTO