\begin{table}%t5
%\centering
\par
\caption
{Coefficients of the WLR obtained in the present investigation (discarding
HD~93129A and HD~303308 from the regression), compared to the results from
Paper~I and the theoretical prediction by \citet{Vink00}. Entry 4 and 5
correspond to values obtained by using the "old'' absolute magnitudes
($\rightarrow R_{\rm old}$), entry 6 and 7 correspond to the values derived from new
ones including the results for seven Cyg OB2 stars by \citet{h02}. The
last entry corresponds to the regression performed in Fig~\ref{wlr_all}. 
Present data has been analyzed by accounting for the errors in
both directions and their correlation, whereas 
a standard least square fit has been performed for the data in Paper~I (no
errors available).\label{coeff}}
\begin{tabular}{lllll} 
\hline\hline
\multicolumn{2}{c}{Sample}
&\multicolumn{1}{c}{$\log D_{\rm o}$}
&\multicolumn{1}{c}{$x$}
&\multicolumn{1}{c}{$\alpha'$} \\
\hline
\multicolumn{2}{l}{\citet{Vink00}}&$18.68\pm0.26$ &  $1.83\pm0.044$&  $0.55\pm0.013$  \\    
sg &(Paper~I) &  $19.23\pm0.98$  & $ 1.75\pm0.17$ &  $0.57\pm0.055$   \\
g/d& (Paper~I)&  $18.90\pm1.46$  & $ 1.72\pm0.25$ &  $0.58\pm0.085$   \\
sg &\MV(old)  &  $17.34\pm2.46$  & $ 2.14\pm0.44$ &  $0.47\pm0.096$   \\
g/d&\MV(old)  &  $19.3 \pm1.22$  & $ 1.73\pm0.22$ &  $0.58\pm0.074$   \\
sg &(+CygOB2) &  $17.98\pm1.88$  & $ 2.00\pm0.32$ &  $0.50\pm0.080$   \\
g/d&(+CygOB2) &  $18.70\pm1.29$  & $ 1.84\pm0.23$ &  $0.54\pm0.068$   \\
\multicolumn{2}{l}{"unified'', cf. Fig.~\ref{wlr_all}} 
              &  $18.92\pm0.87$  &  $1.80\pm0.16$&  $0.56\pm0.049$    \\    
              \hline
\end{tabular}
\end{table}