LaTex - longtable og Underfull \vbox warning

I get 'Underfull \vbox (badness 10000)' warning at the line with
\end{longtable}.

I searched Google, and only advices there was to append \raggedbottom
to the preamble. That did not change anything.

\begin{longtable}{|p{6cm}|p{6cm}|}
    \caption{Fly B767-400\label{test1-B767-400}}
    \endlastfoot
    \endfirsthead
    \multicolumn{2}{c} {(\it tabel fortsat...)} \\
    \endhead
    \hline
    \multicolumn{2}{|c|} {\bf Konfiguration} \\
    \hline
        aircraft.actype & B767-400 \\
        aircraft.icao\_code & D \\
        aircraft.speed & 12 \\
        aircraft.towing & false \\
        aircraft.passivemovement & true \\
    \hline
    \multicolumn{2}{|c|} {\bf Forventet resultat} \\
    \hline
        taxiway\_w & true \\
        taxiway\_c\_south & true \\
        taxiway\_n1 & true \\
    \hline
    \multicolumn{2}{|c|} {\bf Faktisk resultat} \\
    \hline
        taxiway\_w & true \\
        taxiway\_c\_south & true \\
        taxiway\_n1 & true \\
    \hline
\end{longtable}

Thanks for any suggestions.