texlive-2009 pdflatex doesn't work (sometimes)

[Matthew Saltzman]

I have two F12 systems with texlive-2009 installed.  On one of them,
pdflatex works fine.  On the other, I get this error:

        $ pdflatex simple.tex 
        This is pdfTeX, Version 3.1415926-1.40.10 (Web2C 2009)
        
        kpathsea: Running mktexfmt pdflatex.fmt
        I can't find the format file `pdflatex.fmt'!
        
On the working system, pdflatex.fmt is in
${HOME}/.texlive2009/texmf-var/web2c/pdftex/pdflatex.fmt, but on the
failing system, that file is missing.

Reinstalling and rerunning texconfig doesn't help.

Any idea what's going on?

TIA.
-- 
                Matthew Saltzman

Clemson University Math Sciences
mjs AT clemson DOT edu
http://www.math.clemson.edu/~mjs