[Gretl-users] F statistic not showing with HAC errors

I am doing a manual 2SLS, and so i need an F statistic to check the independent variable in the first stage is above 10 and a suitable IV. When i do classic errors i get an F stat of 82 (although it's unclear if this is for the whole regression or just my independent variable). As my data has autocorrelation I would like to use HAC errors, however when I do an F statistic is not computed and so I cannot see if my IV is strong. Can anyone help?