[Tex/LaTex] Matrix equation and \notag

Question

My problem is related to the following "equation":

\begin{align}
\left(
\begin{matrix} 
    \shat{X} \notag \\ 
    \shat{X}' \notag \\ 
    \shat{Y} \notag \\ 
        \shat{Y}' \\
    \end{matrix} 
\right)_{n+1} 
= R(\omega_x, \omega_y) 
\left(
    \begin{matrix}
        \shat{X}  \\
        \shat{X}' + \shat{X}^2 - \chi \shat{Y}^2 + \kappa \left( \shat{X}^3 - 3 \chi \shat{X} \shat{Y}^2 \right)  \\
        \shat{Y}  \\
        \shat{Y}' - 2 \chi \shat{X} \shat{Y} - \kappa \left( \chi^2 \shat{Y}^3     - 3 \chi \shat{X}^2 \shat{Y} \right)  \\
    \end{matrix}
\right)_n 
\end{align}

It looks like I have to use notag for each line to avoid the individual line/equation numbering. Why is that ?

The next problem is: when I use 'notag' for each line, then the result is completely ugly, and the delimiters are in the wrong order (something strange with ) before ( …

I'm using memoir with amsmath.

EDIT:

The shat command is defined as

\newcommand{\shat}[1]{\ensuremath{\hat{#1}}}  

and it seems to work.

The problem looks the same for this simpler case:

Answer 1

Cannot reprocude the problem, please post a full minimal example. This (using pmatrix works fine)

\documentclass[a4paper]{memoir}
\usepackage{amsmath}
\newcommand{\shat}[1]{\ensuremath{\hat{#1}}}  
\begin{document}
\begin{align}
\begin{pmatrix} 
  \shat{X}  \\ 
  \shat{X}' \\ 
  \shat{Y}  \\ 
  \shat{Y}' \\
\end{pmatrix}_{n+1} 
= R(\omega_x, \omega_y) 
\begin{pmatrix}
  \shat{X}  \\
  \shat{X}' + \shat{X}^2 - \chi \shat{Y}^2 + \kappa \left( \shat{X}^3
    - 3 \chi \shat{X} \shat{Y}^2 \right)  \\ 
  \shat{Y}  \\
  \shat{Y}' - 2 \chi \shat{X} \shat{Y} - \kappa \left( \chi^2
     \shat{Y}^3     - 3 \chi \shat{X}^2 \shat{Y} \right)  \\ 
    \end{pmatrix}_n 
 \notag
\end{align}
\end{document}