In the following example document, both \autoref and plain ref will correctly link and number an algorithm reference, but cleveref fails that task. It will just insert question marks instead. In another, far more complex document I have, it does insert correct numbers but links them all to page 1. Since the documentation of cleveref sounds like it should support everything other referencing packages support and more, I'd have hoped this was supported, too.
\documentclass{article}
\usepackage[nameinlink,noabbrev]{cleveref}
\usepackage{hyperref}
\usepackage{algorithm}
\usepackage{algpseudocode}
\providecommand\algorithmname{algorithm}
\begin{document}
We want the real content on page two to better detect errors.
\newpage
\begin{algorithm}
\caption{Incrementation step}\label{alg:inc}
\begin{algorithmic}
\State $x\gets x+1$
\end{algorithmic}
\end{algorithm}
Comparing auto like \autoref{alg:inc},
clever like \cref{alg:inc} % this gives the error message
and manual like algorithm~\ref{alg:inc}.
\end{document}
Compiling the above I get
LaTeX Warning: Reference `alg:inc' on page 1 undefined on input line 18.
If I move the algorithm package before cleveref, I get an error instead of that warning:
(/usr/share/texmf-dist/tex/latex/cleveref/cleveref.sty
! Undefined control sequence.
<argument> \ALG@beginalgorithmic
l.2843 }{}
% end of \@ifpackageloaded{algorithm}
But if I move the algpseudocode before cleveref, I'm back to the beginning.
This is a Gentoo texlive 2012 installation, with the following packages involved:
- cleveref 2012/03/07 v0.18.5
- hyperref 2012/05/13 v6.82q
- algorithm 2009/08/24 v0.1
- algorithmicx 2005/04/27 v1.2

algorithm2ewhich I don't use. And probably won't use any time soon, since it doesn't seem to integrate well with my other plans. – MvG May 11 '13 at 15:06cleverefis quite old (dare I say obsolete?). The most recent version is 0.18.9; among its improvements are several updates to keep up with recent changes in some of the algo packages... You may want to update all of these packages. – Mico May 11 '13 at 16:16mdframedv1.6b, as opposed to the v1.5 on my OS X. And 1.6b requires a fix to work withamsthm. So my belief that unmodified texlive releases would be a good foundation for portability is not as strong as it used to be. – MvG May 11 '13 at 16:23