Sometimes, however many times you run LaTeX, the cross-references
are just wrong. A likely reason is that you have placed the label
before the data for the label was set; if the label is recording a
\caption command, the \label command must appear
after the \caption command, or be part of it. For example:
\begin{figure}
\caption{My figure}
\label{myfig}
\end{figure}
is correct, as is
\begin{figure}
\caption{My figure%
\label{myfig}}
\end{figure}
whereas, in
\begin{figure}
\label{myfig}
\caption{My figure}
\end{figure}
the label will report the number of the section (or whatever) in which
the surrounding text resides, or the like.
You can, with the same malign effect, shield the \caption command
from its associated \label command, by enclosing the caption in an
environment of its own. This effect will be seen with:
\begin{figure}
\caption{A Figure}
\end{figure}
\label{myfig}
where the \label definitely is after the \caption,
but because the figure environment closed before the
\label command, the \caption is no longer “visible”.
In summary, the \label must be after the command that
defines it (e.g., \caption), and if the \caption is inside
an environment, the \label must be in there too.
This answer last edited: 2012-02-07
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