Power driver seat moves by itself while driving
 

I have an 06 Pacifica Limited. The driver seat does have the memory function with the 12 way switch for the driver seat. The driver seat will move all on it's own while driving, and you cannot override it by using the power seat switches. The memory function will not move the seat back to position either while the car in in gear. The memory seat function will work with the vehicle in park.. But while driving, the seat will randomly start to move. It goes all the way up toward the wheel and tilts the front of the seat all the way up. This can be dangerous to a guy who needs the seat all the way back! Anyone know what will cause this? All positions work with the exception of the front tilt as far as the switch goes, and I know it's the switch because the motor is working fine when you use the memory switch. It will do this at random while driving...No rhyme or reason. It happens a few times a week.