[XeTeX] Overlapping vocal over hamza letter (Arabic)

[Meho R.]

Hi,

I updated my TL installation to TL2010 and noticed that damma is overlapping 
hamza using Uthman Taha font (the font is free and can be obtained 
here: http://fonts.qurancomplex.gov.sa/). This doesn't happen with TL2009.

Since I still have a local installation of TL2009, I tried to replace all 
packages which may be the cause for this issue (xelatex, polyglossia, bidi...) 
with the ones from TL2010, but with no avail. Can anyone advise?

Here's an example code for testing purposes:

\documentclass{book}
\usepackage{xltxtra}
\newfontfamily\arabicfont[Script=Arabic,Scale=2]{KFGQPC Uthman Taha Naskh}
\usepackage{polyglossia}
\setmainlanguage{croatian}
\setotherlanguage{arabic}
\begin{document}
\textarabic{ءُ}
\end{document}

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://tug.org/pipermail/xetex/attachments/20100914/d6ba172f/attachment.html>