[XeTeX] ArabXeTeX Translit

[Mohammad Gharaibeh]

Hallo folks,

is there any reason why arabxetex in transliteration does 
not capitalize the shin and the alif mamduda? for the 
other letters there is no problem except those two 
letters.

\documentclass[12pt,a4paper]{book}

\usepackage{xltxtra}

\usepackage{arabxetex}

\setromanfont{Basker Trans}

\newfontfamily\arabicfont[Script=Arabic,Scale=1.5]{Scheherazade}

\SetTranslitConvention{dmg}
\SetTranslitStyle{\upshape}

begin{document}

\textarab[trans]{\UC ^s \UC _d \UC .t \UC _t \UC A \UC a 
\UC .s \UC .d \UC .h \UC x \UC .z \UC U \UC I \UC j}


\end{document}

regards
Mohammad Gharaibeh