As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#1408, CDG-JFK. (ETOPS) (AIRCRAFT DIVERTED TO LHR) 'FLIGHT MANAGEMENT COMPUTERS GIVING ERRONEOUS INFORMATION IN FLIGHT. BOTH COMPUTERS WERE HAVING FLUCTUATIONS IN BOTH TIMES TO FIXES AND DISTANCES. DESTINATION DISTANCES RANGED FROM 3000 MILES TO 9999 MILES. TIMES VARIED FROM 1 TO 10 HOURS. FUEL VARIED FROM 8.0 AT LANDING TO -56.0 AT LANDING; REMOVED ADN REPLACED FMGC #1 IAW AMM 22-82-34. OPS TEST OK. CROSSLOAD COMPLETED AND ALL SOFTWARES MATCH. A/C OK TO CONTINUE FOR SERVICE