st: reg with robust, F-stat reported as a dot.

[f_ciocchini@uca.edu.ar]

Dear Statalisters:

I'm running simple OLS regressions with robust standard errors.
In some cases the F-stat of the regression and Prob>F are reported as a dot
".", like in the example below.
The problem does not show up if I run the same regression without robust
standard errors.
Can someone tell me what can be going on here?
Thanks,
                 Francisco.

Regression with robust standard errors                 Number of obs =
1175
                                                       F( 25,  1148) =
.
                                                       Prob > F      =
.
                                                       R-squared     =
0.6376
                                                       Root MSE      =
.55503

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