I am experiencing this exact problem in my 96. It only happens once in a blue moon though. Sure wakes you up when it happens .

99 CSVT Green/Tan # 84 of 2760 Built on Wednesday, September 30, 1998 15.376 @ 92.00 MPH Stock 75,000Km 96 Contour GL 2.5L V6 ATX 170,000Km