In 2004 in the SAAB I had a false loc/gs capture going into PWM. We were maybe 6 miles south of the ILS 11, due south of AIMME, at about 5000 ft day VFR. The autopilot was engaged and the approach mode armed. The loc and gs captured. Chasing the signals the aircraft instantly and suddenly pitched down about 10 degrees, maybe a little more, and banked to the right. I clicked off the a/p and recovered. It was disconcerting to say the least.