With the following M(ish)WE, I expected the numbering of my examples list to be reset at the opening of the second chapter, but it is not.
\documentclass{book}
\usepackage{chngcntr}
\usepackage{enumitem}
\newlist{examples}{enumerate}{1}
\setlist[examples,1]{label=(\arabic*),resume,}
\begin{document}
\chapter{Foo}
\counterwithin{examplesi}{chapter}
\counterwithin{enumii}{chapter}
\begin{examples}
\item One
\end{examples}
\begin{examples}[resume]
\item Two
\end{examples}
\begin{enumerate}
\item One
\end{enumerate}
\begin{enumerate}[resume]
\item Two
\end{enumerate}
\chapter{Bar}
\begin{examples}
\item One expected; three employed
\item Two expected; four employed
\end{examples}
\begin{enumerate}[resume]
\item One expected; three employed
\end{enumerate}
\begin{enumerate}[resume]
\item Two expected; four employed
\end{enumerate}
% The problem is exhibited above.
% Here on additional is material that might shed some light.
\counterwithin{enumi}{page}
\begin{enumerate}[resume]
\item repeat enough to consume an entire page
\item on compile, enumerate is reset (several lines after) page break
\item The several lines after is a puzzle, but not my present concern
\item It suffices to show chngcntr has effect in
presence of enumitem and \verb|[resume]|
\end{enumerate}
\begin{examples}
\item I would never want \emph{this}
\item But, it seems to show that
\chapter{Baz}
\item chngcntr can reset the examplesi counter
\item but only in examples enviros with embedded chapter commands.
\end{examples}
\end{document}
The immediate question is how can I attain my expected effect?
I did try including a \setcounter{examplesi}{0} after the \chapter commands, but this did not help.
To avoid the X-Y Problem, here's my motivation:
I am working on a textbook and want to have numbered example sentences with a continuous numbering independent of all other numbering in the document, save that I also want the numbering to reset with each new chapter. Ultimately, I want cross-refs within each chapter to use only the example number and from one chapter to an example in another chapter to use the form \thechapter.\theexamplesi I was going to worry about the difference between inter and intra chapter references once I got the numbering sorted; I mention it here chiefly to avoid (if possible) solutions to the present problem which will complicate the second stage.

\makeatletter\@addtoreset{examplesi}{chapter}\makeatotherseems to solve the first problem. – Werner Nov 11 '11 at 17:21