Apparent hyperref conflict with datatool and longtabu col vertical alignment?

Question

Only when I turn on hyperref do I get a weird vertical alignment problem in the first column of a datatool-driven longtabu. Without hyperref, the rows of the first column are vertically aligned to the top just like the other columns. With hyperref turned on, the first column rows are acting like they have a built-in line break and drop down one line within the wrapped column.
MWE -- compare hyperref commented to uncommented:

\documentclass[12pt]{article}

\usepackage{filecontents}
\begin{filecontents}{actionitems.csv}
ID|Project|Opened|Due|Issue|From|Lead|Closed|Note
1|Area 51|2012/12/12|2012/12/21|Prepare for the ending of the world|A. Crackpot|So Crazy||12/12 Survived the trial day \DTLpar 12/22 Bored now -- go on to the next thing
2|Roswell|2012/12/12|2012/12/21|Prepare for alien abduction|Tinfoil Hat|I.M. Gullible||12/21 Where are they? \DTLpar 12/22 Left Behind!
\end{filecontents}

\usepackage{datatool}
\DTLsetseparator{|}
\DTLloaddb{actionitems}{actionitems.csv}

\usepackage{fullpage}
\usepackage{booktabs,longtable,tabu}
\usepackage{pdflscape}

% Note difference in vertical alignment of ID column with package hyperref commented or not:
\usepackage{hyperref}

\begin{document}
\pagestyle{empty}
\tabulinesep=1mm
\begin{landscape}
\begin{longtabu}{ X[1,r] X[2,l] X[2,l] X[2,l] X[5,l] X[3,l] X[5,l] }

    \caption*{Open Action Items}\\
    \toprule

    ID & Project & Opened & Due & Issue & Lead & Note\\ \hline
    \endhead

    \DTLforeach*{actionitems}
        {\id=ID,\project=Project,\opened=Opened,\due=Due,\issue=Issue,\lead=Lead,\note=Note}
        {\id & \project & \opened & \due & \issue & \lead & \note\\ \hline}

\end{longtabu}
\end{landscape}
\end{document}

Answer 1

The behaviour is typical of the behaviour when a \special or other whatsit node appears in vertical mode. The document grfguide discusses this in the context of colour specials but it is a general problem.

The solution is the same as for colour, avoid the problem by getting in to horizontal mode.

This seems to work OK

\begin{longtabu}{ >{\mbox{}}X[1,r] X[2,l] X[2,l] X[2,l] X[5,l] X[3,l] X[5,l] }
%                 ^^^^^^^^^^