In the following example:
\documentclass{memoir}
\usepackage{cleveref}
\newsubfloat{figure}
\begin{document}
\chapter{Example}
\begin{figure}
\centering
\subtop[apple]{fig 100a\label{fig:100a}}\\
\subtop[orange]{fig 100b\label{fig:100b}}
\caption{Can you handle subfigures?}
\label{fig:100}
\end{figure}
\cref{fig:100a} and \namecref{fig:100b}.
\Cref{fig:100}
\end{document}
Both \cref{fig:100a}
and \namecref{fig:100b}
produce ??
The versions of packages used are: cleveref.sty 0.17.2 and memoir.cls v3.6.
Best Answer
You should contact Toby Cubitt, the author of cleveref. He is very responsive to bug reports and the memoir support of cleveref is very new and little tested.
The problem is that memoir redefines
\label
within subfigures, so the cleveref version does not get used...In the meantime, it's not pretty, but this works for your example at least: