beamer problem

[Emden R. Gansner]

When running pdflatex using beamer, I get the error

   LaTeX Error: File `pgfcore.sty' not found.

I see that this was an error last summer and I assume it has been fixed, so is there something else
I need to do? The beamer.cls is coming from 
/opt/local/share/texmf-texlive-dist/tex/latex/beamer/beamer.cls
but the only pgfcore.sty I can find is /opt/local/share/texmf/tex/latex/pgf/basiclayer/pgfcore.sty

Thanks.

     Emden