We Have Measured and Calculated Fully Differential Cross Sections for Vibrational Dissociation Following Capture in 75-KeV P+H2 Collisions. for a Molecular Orientation Perpendicular to the Projectile Beam Axis and Parallel to the Transverse Momentum Transfer We Observe a Pronounced Interference Structure. the Positions of the Interference Extrema Suggest that the Interference Term is Afflicted with a Phase Shift Which Depends on the Projectile Scattering Angle. However, No Significant Dependence on the Kinetic-Energy Release Was Observed. Considerable Discrepancies between Our Calculations and Experimental Data Were Found.