If not, do it – it rebuilds TeX's lsR database, used by <tt>kpathsea</tt> to find your files.
(In MikTeX there's a similar command, "rebuild database" or the like.)
'''Second Hint:'''
You changed/installed something and it doesn't get used?
Did you run <tt>texexec --make -all</tt> after unpacking the archive?
If not, you probably should
'''Third Hint:'''
You changed/installed something, you updated the formats, but something still doesn't work?
Have you checked that your <tt>cont-sys.tex</tt> (and perhaps
<tt>cont-usr.tex</tt>) is still up-to-date with the latest distributed
<tt>cont-sys.ori</tt> (<tt>cont-usr.ori</tt>)?
'''More Hints:'''