As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - APU AIR HAS UNUSUAL AND PERSISTANT ODOR. PLACED APU ON MEL 49-00-1. MEL CLEARED 3/11/09 INSPECTED APU COMPARTMENT. NO DEFECTS NOTED. RAN APU. NO UNUSUAL ODOR FOUND. SYSTEM OPERATES NORMALLY. AIRCRAFT RETURNED TO SERVICE. NO PARTS REPLACED.