SplineSurface Handle problems in OCC ?

Imagine you want to create a BSplineSurface over an array initialized with valid point sample data. Therefore you write something like:

#include
...
int main(...)
{
Handle( Geom_BSplineSurface) surf;
TColgp_Array2OfPnt array( 1, 3, 1,10);

GeomAPI_PointsToBSplineSurface makeSurf;
makeSurf.Interpolate( array);
surf = makeSurf.Surface();

// until here anything is wonderful as it should be

// now let us try to get access on the number of u/v-points of the BSplineSurface
surf->NbUPoles();

// forget it, the compiler will now complain with some crap message as irrational as crap can be

}

This is the message:
invalid use of undefined type `class Geom_BSplineSurface
Handle_Geom_BSplineSurface.hxx:33: forward declaration of `class Geom_BSplineSurface'

=> The compiler is offended by the above line "surf->NbUPoles();"
But it makes no sense !

He complaints about all attempts to acces any kind of classmethods of Geom_BSplineSurface.

I tried excactly the same with a Geom_BSplineCurve and a 1-dimensional array of points.
It worked wonderful, no complaints by the compiler.

I felt like a new bug by the Matra team in our OCC-library.

Is this correct or not ?
Why this stupid useless time-consuming compiler messages ?

Any hint of, i.e. of the responsible persons for that class-code is most welcome.

Regards

MCV