Several Permalloy (Ni81Fe19) films have been prepared by electron beam evaporation, using lithographic masks to shape 5 contacts for simultaneous measurement of longitudinal and transverse voltages with respect to the current j parallel to (x) over cap. The magnetic field H orientation with respect to the film plane and its normal was characterized by the polar theta and azimuthal phi angles. We observed that the transverse voltage V-t (containing extraordinary Hall and planar Hall voltages) as a function of phi, theta and H, exhibits strong and sharp variations when H is nearly perpendicular to the film. A simple model is proposed, taking into account a small misalignment between the plane where H rotates and the true normal to the film, which gives a reasonable explanation of the observed phenomena. The validity of this model near the low field limit is discussed.