Footnote mark alignment with italic text

Question

Possible Duplicate:
superscripts with xelatex? (footnotes, natbib)

I'm adding a footnote to a sentence that is italicized, and the placement of the footnote mark seemed to be off. I'm guessing this is because footnote places the mark as a superscript, and because italicized text is a bit lower, the vertical alignment is no longer correct. Here's a MWE. I am using LuaLaTeX.

\documentclass[lettersize,14pt,twoside,openright]{memoir}
\usepackage[symbol]{footmisc}
\usepackage{xltxtra}
\usepackage{xunicode}
\defaultfontfeatures{Scale=MatchLowercase,Mapping=tex-text}
\defaultfontfeatures{Ligatures=TeX}
\setmainfont[Ligatures=Rare, Numbers={OldStyle, Proportional}]{Adobe Caslon Pro}
\newfontfamily\temp[Ligatures=Rare, Numbers={OldStyle, Proportional}, Style=Historic]{Adobe Caslon Pro}
\newcommand\tracked[1]{%
  {\addfontfeature{LetterSpace=2}#1}}
\makeatletter
\renewcommand{\@makefnmark}{\hbox{\textsuperscript{\large{\@thefnmark}}}}
\makeatother
\begin{document}
\textit{Utinam tam facile possem vera reperire, quam falsa convincere.}\footnote{Cicero. \textit{de Natura Deorum}, I, 91. [\textit{Trans.}]}
\end{document} 

Is there a way to lower the asterisk a bit? I'm also thinking of making the mark bigger by redefining \@makefnmark, so a way to directly control vertical placement would be nice.

EDIT: I just tried my MWE with pdfLaTeX and it works for some reason. I'm using LuaLaTeX with Adobe Caslon Pro.