As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5856, IAH TO STL. DURING CRUISE AT FL370 THE FLIGHT CREW REPORTED THAT THE CABIN ALTITUDE WAS SLOWLY RISING PAST 9,000FT. THE CREW DESCENDED TO FL250 AND AS THE CABIN ALTITUDE CONTINUED TO RISE, THE AIRCRAFT DESCENDED TO FL100 WHERE THE CABIN ALTITUDE REMAINED AT 10,000FT MSL. THE AIRCRAFT DIVERTED TO LIT AND LANDED WITHOUT INCIDENT. IN LIT ON-CALL MAINTENANCE PLACED THE AUTO-PRESSURIZATION SYSTEM ON MEL AND PERFORMED PRESSURE CHECKS ON THE GROUND WITH NO FURTHER DEFECTS NOTED. THE MEL WAS CLEARED IN STL WHEN THE ELECTRO-PNEUMATIC OUTFLOW VALVE WAS REPLACED. THERE WERE NO FURTHER DEFECTS NOTED.