When the LaTeX 2e and XeTeX writers convert a .. contents:: directive into LaTeX/XeTeX, they place an explicit \pdfbookmark[1]{Contents}{contents} command before the \tableofcontents so that the resulting PDF will have a bookmark for the table of contents. However, the \tableofcontents command in the memoir class already includes a "Contents" entry, along with a "Contents" PDF bookmark, and so setting --documentclass=memoir ultimately results in a PDF with two consecutive "Contents" bookmarks.
Eliminating the duplicate bookmark in memoir documents can be done either by omitting the explicit \pdfbookmark command or by using the memoir-specific \tableofcontents* (note star) command instead of the regular \tableofcontents command.
The following files are attached:
dupcontents.rst — a sample input file that leads to the above-described behaviordupcontents.tex — the output from rst2latex.py --documentclass=memoir dupcontents.rst; typesetting this by running pdflatex dupcontents.tex twice produces a PDF with two "Contents" bookmarks
Fixed in r8523.
Thank you for reporting.
Fixed in Docutils 0.17.
Thanks again for the report.