I get an error in my document in the following circumstance:

1. Using the `cleveref` package
2. And the `tikz-qtree` package (for drawing syntax trees)
3. Inside an `enumerate` environment

Here's a MWE:

```
\documentclass{article}

%\usepackage{cleveref} %Uncomment for crash

\usepackage{tikz}
\usepackage{tikz-qtree}

\begin{document}

\begin{enumerate}
  \item foo
    \begin{tikzpicture}
        \Tree [.Foo Bar ]
    \end{tikzpicture}
\end{enumerate}

\end{document}

```

Here's a link to the log that running that file (with `cleveref` uncommented) generates: [log file](http://www.ling.upenn.edu/~ecay/test_tikz.log). The first error is:

```
! Package tikz Error: A node must have a (possibly empty) label text.

```

I've verified the following things:

* It is not a catcode problem, i.e. the
catcode of `.` and `[` is 12 both with
and without loading `cleveref`
* The problem goes away if the tree is
not embedded in an enumerate, i.e.
delete the entire document body and
replace it with only the
`\begin{tikzpicture}...\end{tikzpicture}`
* The problem goes away if you change
the `enumerate` to `itemize`

I tried running the example with `\traceon` from the `trace` package, but got mired in the half-million(!) lines of output.

Based on the esoteric combination of packages, I'm not sure a ready answer exists, but hopefully there is a TeX guru out there familiar with the guts of these packages who sees something I cannot.