Probit model_warning message on the equation output

[Anne_Katy]

Hi all,
I run a probit model (only with two regressors) and I get the following warning message on the equation output:
"WARNING: Singular covariance - coefficients are not unique
Covariance matrix computed using second derivatives
WARNING: Complete separation detected at estimated parameters (results
may not be valid)"

Why does this happen? which is the problem? Can someone help me?
Thanks in advance.
Anne

[trubador]

Hard to say without seeing the actual workfile. But the following discussion might be helpful: http://forums.eviews.com/viewtopic.php?f=4&t=4257

[EViews Glenn]

The manual has (what I hope is) a clear description of the meaning of this warning.