[pstricks] introducing pstricks and pst-node causing figure and table problema

[Michael J May]

Hello,

I am trying to begin using pst-node to do some simple drawing of figures 
in my paper, but I am hitting a strange error.  Just by entering the 
command:

\usepackage{pstricks, pst-node}

I get the following errors for all of my figures, tables, and other 
custom environments on compilation:

! Too many }'s.
\color at endbox ->\color at endgroup \egroup

l.325 ...l matrix under Graham/Denning}\end{table}

?

This is without putting in any pstricks code at all, just by using the 
style file.  Are there any known conflicts that would be causing this? 
The full list of style files that I'm using is:

\usepackage{amsfonts, amsmath}
\usepackage{url}
\usepackage{enumerate}
\usepackage{setspace}
\usepackage{amssymb}
\usepackage{pstricks, pst-node, pst-tree}

Thanks.

Michael