minted truncates the code if it doesn't fit into one page

Unfortunately, this behaviour is due to a known bug. Worse, I have no idea how to fix it.

In the long run, I plan to get rid of the fancyvrb package altogether since strictly speaking minted doesn’t need the verbatim capabilities – LaTeX sequences get escaped anyway. This would lead to a lot more flexibility.

For now, though, this is unfortunately not a trivial change. If you want to get your hands dirty you can try \letting \Verbatim and \endVerbatim to \relax, and then tinkering a bit to get the rendering right again. Disclaimer: I haven’t tried this.

The bad behaviour of the minted package in truncating code can be prevented through the mdframed package. Example:

\begin{mdframed}[linecolor=black, topline=true, bottomline=true,
  leftline=false, rightline=false, backgroundcolor=yellow!20!white]
    \begin{minted}[mathescape]{c++}
        int main()
            {
                bla bla...
            }
    \end{minted}
\end{mdframed}

Obviously you should have package mdframed loaded in your preamble, simply by \usepackage{mdframed} and eventually with global options. Even better, without pasting:

\begin{mdframed}[linecolor=black, topline=true, bottomline=true,
  leftline=false, rightline=false, backgroundcolor=yellow!20!white]
    \inputminted[fontsize=\scriptsize, linenos, frame=lines]{c++}{path/to/your/code.cpp}
\end{mdframed}