Sub Articulo 46.0

Something seemingly strange has happened while processing aoducment
using LaTeX2e: the table of contents, as it appears in the .dvi file,
lists only the parts (I'm using the article format), not the sections
and subsections as it did before.  This happened once before, and the
problem went away, but seems consistent now, even after running LaTeX
about 5 times on the file.  I've got a feeling that there must be
something that I'm doing wrong that's causing this.
The .toc file contains all of the sections and subsections.  Is
there something that I should be doing to force these to appear
in the table of contents?