Amsmath has problems with $e^{\sum{x}}$

Question

Running the code:

\documentclass{article}
\usepackage{amsmath}
\begin{document} Test: $e^{\sum{x}}$ \end{document}

Dies, yet it runs just fine with the \usepackage{amsmath} commented out. The logs show:

!pdfTeX error: pdflatex (file fmex7.pfb): cannot open Type 1 font file for reading

Which seems to indicate a missing font. I've used amsmath quite a bit in the past and never come across the problem. A bit of googleing shows some other Debian users have had this problem but I'm not quite sure what to do here. I'm running Ubuntu 10.04 with most LaTeX packages installed.

Answer 1

This seems to be caused by an out-of-date $HOME/.texmf-var folder. Simply deleting that folder should solve the problem.

(I like Ubuntu, but its TeX packages are a mess.)