Problem with labeled equations in beamer: Why do the labels have different positions after each compilation?

Question

I'd like to make a slide in beamer with a few equations that labels the parts of the last equation shown. I'm doing this with overlays so one equation is added at a time, and only that last equation shows is labeled.

In one approach I've tried, the position of the labels changes each time I compile the file. Specifically, the labels move something like \vspace{0.05cm} upward or \vspace{-0.05cm} downward each time I compile, depending on whether the label is above or below the equation. I want these labels to stop moving on their own. Compile the file about 20 times and you'll see a huge change.

I am also having the problem sometimes that the equation is not all aligned. In the following example, the "Max" is not aligned with the rest of the equation.

\documentclass[professionalfonts, smaller]{beamer} 
\usetheme{CambridgeUS}
\usepackage{tikz}
\usepackage{iwona}
\usepackage{amsmath}
\usepackage{mathtools}
\usetikzlibrary{arrows,shapes}
\DeclareMathOperator*{\Max}{Max}

\begin{document}

\tikzstyle{every picture}+=[remember picture]

\everymath{\displaystyle}

\begin{frame}
\frametitle{Slide Title}

\tikzstyle{na} = [baseline=-.5ex]

  \vspace{1cm}
 \hspace{0.0cm} Comment on x \tikz[na] \node[coordinate] (n1) {};
 \hspace{1.25cm} \tikz[na] \node[coordinate] (n2) {}; Comment on p(x)
 \vspace{0.0cm}
 \begin{equation*}
        \hspace{-4.5cm}
        \tikz[overlay, remember picture, baseline]{
             \node[anchor=base](t1){$\Max\limits_x$};
         }
        \tikz[overlay, remember picture, baseline]{
         \node[anchor=base, right of=t1, node distance=30pt](t2){$L(x) =$};
        } 
        \tikz[overlay, remember picture, baseline)]{
            \node[anchor=base, right of=t2, node distance=35pt](t3){$p(x) +$};
        } 
        \tikz[overlay, remember picture, baseline)]{
            \node[anchor=base, right of=t3, node distance=29pt](t4){$\gamma d(x)$};
        }
\end{equation*}

  \vspace{0.4cm}
  \hspace{0cm} Comment on L(x) \tikz[na]\node [coordinate] (n3) {}; \hspace{1.5cm}   Comment on \tikz[na]\node [coordinate] (n4) {}; d(x)

\begin{tikzpicture}[overlay]
    \path[->](n1) edge [bend left] (t1);
    \path[->](n2) edge [bend right] (t3);
    \path[->](n3) edge [bend right] (t2);
    \path[->](n4) edge [bend right] (t4);
\end{tikzpicture}

\end{frame}
\end{document}

Answer 1

OK, I trimmed down the file quite a bit but here is something I think is closer to you want:

\documentclass{beamer} 
\usetheme{CambridgeUS}
\usepackage{tikz}
\usetikzlibrary{arrows,shapes}
\DeclareMathOperator*{\Max}{Max}

\tikzstyle{every picture}+=[remember picture]
\newcommand\na[1]{\tikz[baseline=-.5ex]{\node[coordinate] (#1) {};}}
\newcommand\ta[2]{\tikz[baseline]{\node[anchor=base] (#1) {#2};}}

\everymath{\displaystyle}

\begin{document}

\begin{frame}
\frametitle{Slide Title}

Comment on x  \na{n1}
\na{n2} Comment on $p(x)$
\begin{equation*}
        \ta{t1}{$\Max\limits_x$} \ta{t2}{$L(x)$} = \ta{t3}{$p(x)$} + \ta{t4}{$\gamma d(x)$}
\end{equation*}

Comment on L(x) \na{n3}
Comment on \na{n4} $d(x)$

\begin{tikzpicture}[overlay]
    \path[->](n1) edge [bend left] (t1);
    \path[->](n2) edge [bend right] (t3);
    \path[->](n3) edge [bend right] (t2);
    \path[->](n4) edge [bend right] (t4);
\end{tikzpicture}

\end{frame}
\end{document}

• I deleted all the \hspace and \vspace commands. Usually there's a better way to achieve the spacing you want than to hardcode it.
• I macro-fied the tikz nodes that just mark nodes for the arrows to connect. It makes the code within \begin{frame}...\end{frame} a bit more readable.
• I deleted the only<1>{...} part because you said you wanted it all one slide/overlay. If you want fancier revealing ask another question.

Hope that helps.