TikZ in (sub)section title

Question

Possible Duplicate:
How to add a tikz/pgf command to section command

I would like to add a tikzpicture to a section title using:

\newcommand*\circled[1]{\tikz[baseline=(char.base)]{
\node[shape=circle,draw,inner sep=1pt] (char) {#1};}}

and include it in a section:

\section{\circled{A}: Tool 1}

However, the following error message pops up:

! Use of \tikz@picture doesn't match its definition.
\pgfutil@ifnch ...ved@c \pgfutil@reserved@a \else 
                                                  \let \pgfutil@reserved@c \...

Using \protect did not do the trick.