What was found
FLT 1090 - LSE-MKE - SHORTLY AFTER TAKEOFF, THE GPWS COMMANDED PULL UP, PULL UP. THE CREW CONTINUED TO CLIMB BUT THE GPWS WOULD NOT STOP, SO THE CREW MADE AN AIR-TURN-BACK AND AN UNEVENTFUL LANDING. MAINTENANCE WAS CONSULTED AND THE GPWS WAS PUT ON MEL. MAINTENANCE CLEARED THE MEL NOT BEING ABLE TO REPRODUCE THE EVENT. LATER GPWS WAS PUT ON MEL AGAIN. MAINTENANCE INSPECTED THE SYSTEM, REPLACED THE GPWS COMPUTER AND OP CHECKED GOOD. THE A/C WAS RETURNED TO SERVICE. (M)