What was found
AT FL380 JAKARTA ATC SAID WE WERE INDICATING FL367. WE WERE INDICATING FL380 CAPTAIN, FL380 F/O AND FL381 STDBY. NOTHING ABNORMAL WITH SINGAPORE ATC. CREW DEBRIEF, NO ISSUE WITH SINGAPORE ATC. INSPECTED PITOT TUBE FOR ANY DEBRIS IAW B767 AMM AS ABOVE, NO DEFECT NOTED. PER FIM ABOVE FLIGHT ALTITUDE DIFFERENCES ARE WITHIN LIMIT. A/C OK FOR SERVICE.