When creating a tabu with two rows, I get more vertical spacing after the environment than when I create a tabu with only one row.
In the document below, the first tabu has two lines, and there is a small space between the end of the table and the rule below it. In the second tabu, I only have one line, and there is a larger space below it.
\documentclass{article}
\usepackage{geometry}
\usepackage{tabu}
\geometry{a4paper}
\begin{document}
\begin{tabu} to \textwidth {X X}%
These are words & in the first line \\%
These are more words & in the second line%
\end{tabu}\par%
\rule{\textwidth}{0.4pt}\par%
%
%
\vspace{2em}\par%
%
%
\begin{tabu} to \textwidth {X X}%
These are words & in the first line%
\end{tabu}\par%
\rule{\textwidth}{0.4pt}\par%
%
\end{document}
I've been quite careful (I think) with whitespace around the tabu, and I see no difference in the two tables aside from the different number of lines.
I know that I could fix this by adding a \vspace{0.5em}
or similar right after the tabu with the small spacing, but I am using the tables in a custom command and I would like to avoid a hard-coded solution like this if possible.
This problem also comes up if I substitute a tabular for the tabu. Adding \tabulinesep=Xem
fixes (or appears to fix) the problem for large X (>1em), but I need small spacings (ideally, ~0em).
Any ideas?